In a perfect world, the Evermore Universe crossover with Final Fantasy IV (in Ebon Keep) would be built further upon.
This is something that SE has never seen fit to even try with any of their IPs (with the exception of Dissidia, but the 'story' in that game is so completely devoid of any investment or coherency that I don't think it really counts), and I, for one, think that creating something akin to the MCU for Square-Enix games (The Dragon Quest Series, The Final Fantasy Series, The Mana Series, Evermore, The Chrono Games, et al) would be akin to ... well, to dropping a meteor on the current state of the JRPG market.
FF7 Remake is finally out (episode 1 of it, anyway)... I think, if they're going to make banking on nostalgia their entire deal at this point, then they might as well bank on it full ham, if you get my meaning.
Imagine the possibilities. It'd be a heck of a writing job (I don't even know where to begin imagining how to tie all this ridiculousness together), but at least they own the rights to all the characters, and it would beat the dumb gatcha mobile crap they've been doing with them, any day of the week.