So here's a theory I ran into this evening, that you might have seen as well. I personally feel that with these games having bucked so many trends already trying to predict the future using the past is probably not the best idea, but then again, there is actual evidence for this. Possibly.
So, notice that the Japanese logos for XY contain the Mega Evolution symbol:
And that the Japanese ORAS logos contain each Orb:
Both games contained a new mechanic that went "beyond evolution"--Mega Evolution in XY, Primal Reversion in ORAS--and the symbols for these mechanics are contained within their Japanese logos. So, notice how the Japanese logos for our new games contain a certain symbol as well, those little diamonds in the center?
Some have gone on to say that those look like Burst Hearts, from that manga that still hasn't made its American debut, which allow humans to combine with Pokemon. And so the theory goes that something Ash-Greninja-esque could be making its appearance in Gen VII --recall that it is explicitly stated that Ash-Greninja is
not a Mega, and is thus something else entirely. Also recall that, per official sources, the Ash-Greninja thing is explicitly stated to have happened once before, long ago, in Kalos. So maybe, possibly, stronger evidence for a tieback to Kalos in some way, as a second region a-la the Johto games or something else?
Anyway that's a theory I wish I'd come up with, although it is one I'm a bit skeptical about, but nonetheless one of the stronger and more substantial ones I've seen by far (although that's not saying much). Thoughts?