A lot of concerns have been getting brought up. There's a concern that ZOS may get overwhelmed and brush some aside or ignore some of them. We hope that someone is keeping a list of the concerns but there's no way of knowing if this list exists or not, so I'll post one here. It would be nice if these are discussed whether or not you decide to change them.
In no particular order of frequency or importance, the concerns I see being brought up most are:
1. Templar Jabs & Rapid Strikes animation change
https://forums.elderscrollsonline.com/en/discussion/615703/jabs-old-vs-new/p1https://forums.elderscrollsonline.com/en/discussion/615539/new-rapid-strikes-animation
2. Oakensoul - many of the major buffs were changed to minor, while minor aegis, minor slayer, minor mending, and empower were added. How many more changes to this item should we expect? I say this because people dedicate entire builds and strategies to this item in the short amount of time it's been available. edit: ADDITIONALLY: part of what makes this mythic OP is the heroism, you changed it from major to minor heroism but all that did was make the ball groups run around longer before ult dumping people again. There needs to be removal of heroism as all you need for it to activate is your group member nearby to be in combat, maybe make it deactivate with battle spirit? this seems to be what people who are not myself are suggesting. The major issue: this mythic combined with balorghs gives devastating amounts of penetration (11500 at 500 ult) and spell/weapon damage (500 at 500 ult) for 12 seconds while allowing people to build tanky, and it needs to be addressed.
3. Radiating regeneration + Vigor - why didn't you nerf the amount of radiating regenerations & vigor that can be stacked? You decided to nerf the amount the spell heals instead and increased the tick rate from 1 second to 2 seconds. People can still be near invulnerable if they just get more people to use radiating regeneration & vigor. In fact, Vigor is as effective and hits more people in one cast than RR. Most people other than ball groups rarely have more than 2 radiating regeneration on them at a time, let alone a vigor other than their own. The ball groups are still able to tank and out-sustain
siege weapons, which is often what people resort to because they are able to out-sustain everything else in existence. Players shouldn't have to rely on siege weaponry.
4. "sticky" DoT nerf to viable higher damage dealing DoTs- extending their duration while nearly halving the damage output. You decided that the buffs/debuffs during the duration of these dots was more important than the damage these dots deal themselves, community feedback says damage is important and all you did was mess with rotations. Was this change really about accessibility, or is it to help make fights last longer?
https://forums.elderscrollsonline.com/en/discussion/615863/how-i-lost-65k-dps-and-why-longer-dots-are-way-harder-to-play-with
5. Mara's Balm - there was content creator feedback that this shouldn't have been released in this state, with footage and deliberate drawn-out commentary. We see it in the game, released in that exact state, and we have no viable counters other than DK corrosive ulti to get through people who use it, or of course them being caught in an occult overload + vicious death zerg explosition. Why did you release it in an OP state and why are you deciding to nerf it two weeks later as opposed to sooner? edit: There's people (necros with their health-costing remove debuff ability) running around cyrodiil who can tank 20+ players and seige weapons and just laugh in peoples faces, and the fact that these players can operate seige and light seige on fire as they "troll tank" and stand on flags to capture them does in fact make this set gamebreaking in cyrodiil and even battlegrounds when utilized in this manner.
https://www.youtube.com/watch?v=jH0BRNiq4ko
https://www.youtube.com/watch?v=gW2rAvPffXshttps://forums.elderscrollsonline.com/en/discussion/614654/psa-new-broken-set-that-will-make-you-or-your-enemies-unkillable
6. Increased accessibility to the game - people say your intention was to raise the floor and lower the ceiling. By introducing Mara's Balm in the broken state that it is in for PVP, and not really doing much in changing veteran dungeons (you did change vet trials evidently), you contradict yourself a bit and need to do more prompt tweaking and adjustments
7. Why are there massive swings in the meta every 3-6 months? perspective of a new player:
https://forums.elderscrollsonline.com/en/discussion/616316/a-fan-of-templar-and-the-impact-of-u35
8. Fake tanks and fake healers queuing for dungeons seems to be a persistent problem that even I was ignoring but I see this topic come up a LOT.
here are some RECENT topics talking about it:
https://forums.elderscrollsonline.com/en/discussion/616431/what-is-your-fix-for-the-fake-tank-fake-healer-issuehttps://forums.elderscrollsonline.com/en/discussion/616020/the-amount-of-fake-tanks-and-fake-healers-is-ridiculoushttps://forums.elderscrollsonline.com/en/discussion/616088/to-be-tank-and-play-randoms-dungeoshttps://forums.elderscrollsonline.com/en/discussion/616056/the-hundredth-stop-fake-tanks-plea
9. dungeon/group finder not working properly. I have personal experience with this as do others. If I queue 3 people as a healer, tank, and dps, we will never find the fourth person to dps even if it's a random, whereas if we queue as a healer and tank, and tell the dps to queue separately, it's instant. Additionally, finding someone after someone leaves isn't working as intended even if it's a dps that's needed. Another issue is queuing for specific dungeons, but getting placed in a dungeon we did not choose. The final issue is that if someone rejects the ready check, you don't actually get placed back into queue despite it saying you are in queue, you always have to leave queue and rejoin edit2: after further testing, this occurs on instant-queue selections like tanks, not on DPS choices. edit3: but wait! there's more. Now we have a bug (I personally encountered this and can go back in my footage and provide evidence on request if you send a forum PM to me) that people get kicked from the dungeon immediately upon entering- I can only confirm this is the issue because the tank and healer queued together, and the healer said that the tank did not leave, but was insta kicked from the dungeon. We attempted to reinvite this tank but it was impossible. Another issue I've seen (and is reported in one of the topics below) is that everyone except 1 person will get into the dungeon, and that 1 person will show as offline to the others, but for whatever reason we have to DM the person to enter the dungeon or to change zones so they can see that they are in a group. A final issue that is also described is that in rare instances after a dungeon and returning home, you will be in an older version of your group with everyone offline, it will also show you as queued for a dungeon and you will be unable to leave the group or the queue until you log out (I don't know if I have footage of this one, but I'd be willing to go back into my footage and check if this is still the case).
Here's some topics where people talk about the issues:
https://forums.elderscrollsonline.com/en/discussion/615843/how-long-an-average-does-it-take-you-to-get-a-replacement-for-group-finderhttps://forums.elderscrollsonline.com/en/discussion/615971/dungeon-cueing-is-really-badhttps://forums.elderscrollsonline.com/en/discussion/615383/dungeon-confirmation-bug-removed-from-queue-on-hitting-confirmhttps://forums.elderscrollsonline.com/en/discussion/615384/activity-finder-keeps-surprising-me-with-new-bugs-8-years-laterhttps://forums.elderscrollsonline.com/en-gb/discussion/617175/again-and-again-dungeon-group-finder-toolhttps://forums.elderscrollsonline.com/en/discussion/617120/dungeon-finder-broken-undaunted-eventhttps://forums.elderscrollsonline.com/en-gb/discussion/617177/random-dungeon-finder-issueshttps://forums.elderscrollsonline.com/en-gb/discussion/616835/new-bug-specific-to-matchmade-undaunted-dungeons-pc-na <- I detailed a fix in this one, but it turns out it did not work upon further testing. It might have something to do with companions being summoned, or the dc'd/leaving player being shown as in zone still.
my personal concerns and more obscure concerns:
a. Dark convergence nerf. I was fine with the frequency pre-nerf, but I feel you are nerfing the wrong thing. Primarily because making a set proc only 25 seconds renders it to near uselessness, but you missed the mark on this one majorly. Here is the issue with dark convergence and you didn't fix it:

in PVP, you do an AOE, it procs, and everyone converges onto a single point, straight to the middle and very ult dumpable and very abusable. In PVE you have it so they are kinda pulled toward the center, and they are interrupted so long as they aren't CC immune- some NPCs even roll away or get distance from the center and aren't hit by the effect. Just like with the radiating regeneration "nerf" all you made it is so that groups just need to have more people running this set to abuse it. The frequency was fine, at least give us at least 5 seconds back, but why is this set behaving differently in PVE and PVP gameplay?
edit: below we discuss hitboxes on NPCs vs Players, that NPCs are getting pulled to the center but only at the edge of their hitbox. There are solutions to this issue in PVP but it's not getting addressed. Additionally, there is a suggestion to nerf Rush of Agony as the visual effect of Dark Convergence is the only thing that made people notice it.
b. Ravenwatch and no proc gameplay - can we get a tooltip to state sets work in no proc gameplay? Or at least make it so we can enable that setting in our own homes.
https://forums.elderscrollsonline.com/en/discussion/615358/the-state-of-no-proc-ravenwatch-a-year-later
c. Why did you make Molten Whip half magicka half stam costs? Nobody so far as I can see asked for this. People have been, evidently, asking for a stamina version and this has been ignored for a while
https://forums.elderscrollsonline.com/en/discussion/615697/i-do-not-enjoy-the-new-molten-whip
d. What do you have to say to the people who feel like you are locking endeavors behind a paywall? We looked at the data here
https://benevolentbowd.ca/games/esotu/eso-theorycrafting-endeavors-year-one/4/ but would love to hear your take on things. I personally don't mind- your product, your decisions, but many without all the DLC express a feeling of discontent.
e. Some players are dissatisfied with the communication being received in regard to changes. Some are upset about communication in general. Some seek mere acknowledgment that a change has occurred and that it's not a bug (like Lightning HAs losing a tick). While I don't agree that some of these are top priority concerns, others express this in spades and I would be remiss if I were to not acknowledge them, which is why I can empathize with what having to deal with these sorts of topics can do. How can you help to bridge this gap?
https://forums.elderscrollsonline.com/en-gb/discussion/617242/https://forums.elderscrollsonline.com/en-gb/discussion/616320/
Agree or disagree that these are actual concerns? please state so in a reply.
Will update the list as more people reply with concerns I missed (please link to topics if applicable)
@ZOS_Kevin pinging you in this edit