Do we really think Solas would initiate a kind of Chantry-blowing-up-scenario for the sake of uniting elves? We saw how well that worked with mages (not that well actually, since the CoE vote passed by a very negligible margin) and I don't know if I find that kind of extremism in character for Solas now (maybe before? mistakes of a younger elf and all that)
I don't actually think he would do that. If that was his goal, all he'd have to do is say: "oh, by the way I am an ancient elf and I am the one who caused the breach." He already has done a catastrophic event, albeit accidentally. I don't think he'll then go, "Hey, that was a pretty good idea. Lets do that again, except this time I'll make sure people know elves did it."
Personally, I think he's more likely to do something to save elvhen, and from there, they might go on to trying to unite the other elves. And because of suddenly powerful elves being around, 'normal' elves might get backlash.