That was an interesting read. I must have missed it the first time, thanks for bringing it up here. I had always assumed his line "the return of my people mean the end of yours" meant that both modern elves and other races would perish for the ancient elves to be restored. It feels good to be presented with some hope that this may not be the case after all.
Eh. I all honesty the "he meant that metaphorically vs. literally" argument has been going on ever since trespasser was released.
By and large there is no consensus on the details of his plan to restore "the world of the elves". We can't agree if he wants to save modern elves or just wants to save ancient elves. We can't agree if the 'end of the world' simply means a transformation that destroys the current status quo or the literal destruction of Thedas and its people. We can't even agree on if Solas if what Solas is trying to do has something to do with some other worldly factor (blight, old gods, etc.) and not just Solas's (and his followers) personal plan.
We can't agree because we simply don't know. People say they do....But they don't. Even I don't.
As with everything else, it will have to be revealed in the next game or two (maybe three). But there is always evidence that can support just about anything. I myself am of the mind that during inquisition, there is a decent chance Solas comes to see the modern Thedosians as people, regardless of his relationship of the inquisitor. But just as there is an argument against this theory, there is also an argument for it.
Similarly, the arguments for who or whom Solas views as "his people" have all been done before. He clearly identifies with Sera on some level, and has had attempts to communicate with the Dalish, but then there is that singular line he said after Halamshiral ("our people?"). That one line, and his usual distance that he puts between him and just about everyone--including elves, that make us doubt on who exactly he identifies with. Some even believe he does not so much identify with elves as he does spirits.
So believe what you wish to believe. Until the next game comes out practically everything is fair game, and I myself get bit uplifted when I put a little bit of faith into one of my favorite characters.