It is really baffling how the most lucrative IP in gaming doesn't have a wealth of great programmers modellers to choose from. Nintendo really needs to have one of their sub-studios lend a hand.
Aren't at least the Pokemon models currently in the games higher fidelity (or something like that) than they would actually need be? I've heard that thrown around before. If true, then the models themselves aren't too much of a problem.
Well, if they're correct about Game Freak developing, it couldn't really plausibly be anything but Sun/Moon HD, could it?
A port of a game they released to new hardware, which they've never done before, seems just as likely as a remake of an old game (Gen 1, Gen 4), IMO. We're not expecting a spin off if Game Freak is developing, but it's possible. Game Freak has not exactly "followed the formula" with Pokemon main game releases the last two generations.
A Pokemon game by GF is interesting. They're hardly ending a generation within 1 year, but at the same time, this would cut off compatibility between the same generations (besides Pokebank). Also, the director cut/sequel games have never been released so close after the initial game since Generation II, though I guess it isn't impossible.
That's exactly what PokeBank is made for now, though. If Game Freak is developing a title for NX so early and it's a main game, then there's going to be a first here. Either their first port, the first generation to cross hardware lines, the quickest generation yet in under a year...
The biggest surprise really is that Game Freak would move on to new hardware so quickly.