Type-0 didn't happen, you expect FF12 to be on Vita?
Yes.
Square released X/X-2 HD on Vita, they're making an exclusive SaGa game for it and they seem to port a decent amount of their various mobile games of questionable quality. So why not XII HD?
Type-0 was a whole other ordeal, meant to garner a lot of extra sales from the exclusive XV demo. If that hadn't been the case I imagine the game would probably have been ported to PS3 and Vita also. But who knows, Square's weird and unpredictable.