So I am guessing he wants to make ehlven out of the elves he has.
Maybe, but the survival rate is definitely pretty low. Just like you said regarding the tranquil reversal, even though the elves maybe more attuned to the fade before, after thousands of years of being separated from the fade, they may not have the mental capacity anymore, it's both a regression and an adaptation, the new "synthesis" with fade might just "fry" their minds. The same can be said about the spirits and demons, it would be total chaos for both worlds.
Anyway, I don't see how the modern elves could ever benefit from the current situations. If Solas succeeds, then it's near-total annilation for them; in a more likely scenario where Solas fails, the elves will the target of all other races. The Qunari, Orlais and Ferelden already know this involves an elven god, and now with huge numbers of elven servant leaving the cities, I don't see how the human society could function properly and ignore this. Not to mention if the Tevinter elven slaves were to ever get involved, the empire's whole structure of society might just crumbled. The Imperials might have the highest stakes here.
I know the city elves are pretty disgruntled about their current situation, but I still fail to see how Solas could attract such a hugh following without using false promises and lies by omission, OR maybe they are just THAT willing to sacrifice everything for a better future (for their children?). Still I find this exploitation of their despair and hope somewhat distasteful, reminds me of what Orsino said before he turned Harvester (illusion of hope and such). Maybe the Dalish wouldn't be so easily to swallow his lies because of his reputation, maybe there would be a showdown between the Dalish and the city elves as well as the general "elves against the world".