But the difference there is that those are real games. They fit in and create more canon. The whole point of this game is to give a tiny, vague hint at Kingdom Hearts III.

That's not the whole point of KHX. It's obviously not a game to the magnitude of other Kingdom Hearts titles, but we can't discount it from the Kingdom Hearts universe either. Without word from Nomura on it's canon status, we have to assume that it's just as much canon as any other KH game. Really I think the only thing we know for sure is not canon is the manga.

I get what you're saying and I totally agree, I just don't fault Nomura for it at all because I think it's an understandable situation that can simply be ignored, but that's me. I totally get your viewpoint though, not trying to discredit or anything

Well, there's a KH for cellphone in Japanese, but it's not Coded nor X, just a adaptation of the first KH, and it's nto canon as far as I know.

http://kingdomhearts.wikia.com/wiki/Kingdom_Hearts_Mobile

It could be that they didn't have an idea of what new enemies to create. With Unversed, Heartless, Nobodies, and Dream Eaters, we're already at four. I imagine Nomura probably didn't have much time/didn't think to create a new enemy and just reused previous assets made for the KH Coded avatar section. I do get your point though, there does need to be some clear statement as to whether KHX as a whole is canon or not, but for the art sources I wouldn't be surprised if they used Emblem Heartless just because the resources were already there to use and they could just slap stuff in.