As someone who's been outspokenly pro faction lock, I completely agree with you.

While the change has been positive for the 30 day CP campaign, this drastic change should've come with a one time faction change for all characters.
It's almost unbelievable this was not thought of...but on the other hand, this is Zos...so....yeah

As I always say when this comes up... I am all for faction change, If Done RIGHT!

And by that I don't mean some token that pops your character to a new alliance, I do indeed mean a whole guild-DLC sized questline with an cloak and dagger (Or since this is ESO, "hood and dagger", perhaps?) spycraft flavor and a "faction loyalty called in question" plot, where you get to make a big choice in the middle - stay loyal to your alliance and prove yourself, or turn your back on them and defect to greener pastures elsewhere...

With the second half (or two thirds, or whatever) of the questline being different depending on your choice - either uncovering the one who actually framed you, mobilize your old and trusted allies to gather support and track down the true conspiracy while dodging the agents sent to bring you in; or preparing your escape, dodging the agents sent to arrest you, courting your desired new friends while grabbing some juicy secrets on the way out to sweeten the deal, etc.

Such a story could have a neutral city as "spycraft" focal point (like vienna during the cold war, where spies and agents often went to spy hard between the two sides - for ESO it could be some place between the alliances, a former imperial town declared "free city" after the fall of the empire in northern nibenay, eastern colovia or western skyrim, perhaps, or even an post-anchorite-war isle of stirk...), but otherwise take you all over the old faction regions, possibly revisiting a few one-time-only maps with new mobs... and perhaps even meeting a few familiar faces (come on, wouldn't you love to slam a porticullis shut into Razum-dars face as you hop on a boat bound to Morrowind with thre adorable Naryu? )

Such a questline could even have special titles depending on what you choose... "[original faction] Loyalist" or "[original faction] Defector"... obviously it would be a one-time only event, thus making serial defectors that change alliance depending on which one is currently top in cyrodil that some people always fear when this topic comes up an impossibility.

And it also might have drawbacks for PvP, like... reduced AP gain for several months, since noone fully trusts a traitor... or maybe having to re-earn all the AP up to your current rank before you start progressing again, representing your efforts to convince your new allies of your trustworthyness... and definitely increased AP rewards if a member of your original faction takes you down, because...


(there could even be a daily "hunt traitor" mission, and defectors from your PvP-characters alliance in cyrodil getting an visual clue while that mission is active...)

Also, this could be a option to add new factions to PvP.
And yes, those could be "crown store unlocks"...
Like... have options to not just defect to one of the other two alliances, but also "go rogue" and join a new "Outlaw" faction (...black color and jolly roger flag, perhaps? Would be hostile to -every- other faction in cyrodil, and spawn at some new but unsecured base, thus very susceptible to enemy raids - trials of being an outlaw in the face of organized armies); or an "Imperial Remnant" faction (purple imperial diamond flag, spawning in some ill-secured legion base somewhere, possibly at the nibenay border, and also fighting everyone else, but turning all the "imperial" NPCs in cyrodil non-hostile?), or a "neutral" faction that is "yellow" to everyone (green flag and incapable of capturing locations, spawning at various random merchant camps and such...)
Might be too complicated, but would still be interesting!

Now that they introduced the faction lock, I agree we need to be able of switching alliance. It should be possible with a token, but I don't think "one time" is the solution. Make faction change have a cooldown of like 3-6 months or so. People will still complain about *that* too alright, but at least it's a way to be nice to the ones who made different race characters, and that didn't have "Any race, any alliance" available at that time. Maybe they didn't PVP when they made it, and it's unfair that you'd have to make a new toon and level everything up again, just to be able to use it for the alliance you like.