I don't play in GH so... This is just an opinion, and not a super educated one...

I think lifting the alliance lock would be fine. It seems to me the alliance lock is a tool to prevent everybody from jumping on the winning team. Which is important when that's an option for people. It's important in the lesser populated campaigns.

GH, being the most populous campaign on all servers, really isn't subject to this problem because it's always so full. It doesn't matter if 10 yellows want to jump on red because they're probably going to have to wait in que to do so. And likewise their spots will be filled by the yellows in que. And the population of red can not exceed the cap. So there's no issue.

Please no, because i experienced what would happen last year. Gray Host was broken for about 6 months (on Playstation EU). A maintenance in the middle of the PvP event in July/August 2022 made Gray Host unplayable for almost everyone (except for one youtuber and some other players). Performance was bad before, but this maintenance completely broke it (even on an empty server you would die to guards because you could not use skills etc.). So people started playing on PS NA server instead. Some started playing on PC. And a lot of players just stopped playing PvP and ESO because they didn't want to level and farm everything again.

What was left on PS EU started playing on Blackreach, because for some reason performance was much better there (even with full server). Blackreach has the same rules Gray Host has, but no alliance lock. So exactly what you are asking for here.

At first we were happy to be able to play at all. And it was interesting to play against your own guildmates, friends and your own alliance without spending alliance change tokens, leaving guilds, losing friends...

But then the problems began. Guildmasters started kicking players for playing in other alliances. Groupleaders refused to play on Blackreach. AP boosting and cheating was way worse. Sometimes groups would try to take a keep with a big zerg, and when they saw their attack failing, they quickly swapped char and alliance to collect the huge AP tick for defending the keep they just tried to take. Ballgroups would first farm enemy homekeeps and scrolls, and then switch char and alliance to mock everyone in zonechat. I honestly don't remember everything that happened back then, but it wasn't good for the PvP community.

There is a reason why some people like to play on Blackreach and most players prefer Gray Host. I don't think your idea to get rid of Gray Host and just add another Blackreach would be good for the game.

I am afraid there is nothing they can do to save ESO PvP at this point. The trust is gone. Most people lost hope long ago. ZOS would have to invest a lot more money and add expensive new resources to the game (like PvP developers, better servers for PvP...). And they made it pretty clear that's not what they want to do. PvP went from their biggest selling point to an embarrassing story about neglect and failure. From my perspective it looks like nobody in their team wants to talk about it, nobody wants to touch it, and everyone in their team would like to forget about the whole thing as soon as possible.