I said "Chosen" ones because it is a select group that is going into the metaphorical Noah's ark to sail into the sunset and a brave new world or did i miss the part where everyone will just fall sleep and wake up in the land of milk and honey?
I would presume for one it would be the surviving ancient elves, other than the group at mythrial's temple I seem to recall Solas there were other places where there were still ancient elves remaining that the elves at the temple could join up with. Other than that the dwarves would likely still be kicking and likely a few humans would surivive though the Avvar gods will likely be not amused at the deaths many of their followers and likely neither will the maker who's return has been foretold.
Its not really clear at this point who Solas means to survive this. It could just be the ancient elves, then again he's also including modern elves in his forces.
It's also not clear exactly how removing the Veil will kill everyone. I mean, will re establishing everyone's conscious connection to the Fade kill most people or is it just that the ensuing chaos of removing it will dismantle society and kill a lot of people? I don't know. But I don't think Solas wants to restore the elves because their his "Chosen" people or because he's a supremacist. Rather, he wants to restore them because he's the one that tore them down in the first place.