FFVII would be nigh impossible to translate to a modern game, at most they could maybe gussy it up a bit, but doing a full out remake like that tech demo cutscene isn't going to happen.
TWEWY doesn't have that big of a following, sure it is a cult hit, and has lots of vocal fans, but it's not going to be enough to save them.
KH3, alright this is probably the one big ace up their sleeve right now, and I'm sure they're hard at work on it, but at this point it's been so long that it needs to be perfect. They will take their time with this.
FFXI, lots of people dismissing this game in this thread, but actually it is Square-Enix's most profitable game EVER, and surely that is the driving motivation behind them wanting to make XIV work.
Personally though, I would love for them to revisit old SNES Enix titles, such as Actraiser or E.V.O, but again these are pretty niche titles that would be very hard to pull off as modern games.
So actually it seems like FFXIV might be a good thing for them to focus on for now.