Just because members of the Horde can walk around in it doesn’t mean that it isn’t aligned with the Alliance.
That being said, even if it does turn out to be an entirely neutral city…
It just means that it isn’t aligned with any major power, and doesn’t really have any more implication behind it than it being a modern day cosmopolitan city for a diverse array of Nelves to live.
It’s less of a ‘museum of the old’ and more a emblem of the new.
That’s what the Nelf story has been about since WC3, since the inception.
Change.
The Nelves needed to change in order to beat off the Legion during the Third War.
WoW’s original release dealt with the fallout of that change, and how most of the Nelves which wanted to go back and retreat that ‘old way’ of thinking were ultimately wrong (the original narrative theme of the Teldrassil questchains and Staghelm as a character).
This theme continued on through Cata with the Druids of the Flame and the reincorporation of the Highborne.
This theme continued on through Legion, wherein the Nelves (largely through the Wardens) had to put their pre-conceived hatreds aside and work the the Demon Hunters and Illidan.
It was the theme of Blackrook Hold as well.
This theme was emphasized in the expansions after BfA.
Tyrande, ultimately learns that her self-obsessed quest for revenge wasn’t a path of healing, it wasn’t a path towards a better future.
That’s what the Seed of Amirdrassil represented, a new future for the Nelves.
This theme carries on into this expansion as well.
The entire Nelf Heritage questline centered around the old way vs. the new way.
The new generation against the old generation, and how there’s still challenges yet to overcome.
Most, if not all of the questlines within the Emerald Dream deal with this as well.
Shandris deals with her past trauma, and moves past it, learning that hate isn’t a pathway towards healing and letting go of the past… Looking towards the future.
Like, idk man, there’s a reason that Blizzard decided on creating Nelves in the first place and centering them as needing to change to survive.
This isn’t new, this is just what Nelves are and always have been.
I’m sorry you just haven’t realized that Night Elves have always been a thin allegory for traditionalism vs. progressivism.
…and how embracing change leads to a better future for everyone.