I'd rather they make a new setting and world. If they really had to use an existing setting... mildly curious in how they'd approach Crystal Chronicles, and the races would be different from XI/XIV's basic five, at least somewhat. But even then that's more of a "I wonder how they'd do it" as opposed to "I want them to do that" which is kind of different. Most FF's don't have an MMO tier world. Like VI? Magic is over. The world is ruined, and huge chunks of things in general are removed that would, to me at least, be necessary for a proper FF style. Ivalice is overdone as it is. As you said other races is neat, and most FF's don't have a ton of them. Off the top of my head I could see IX having some diversity on the race standpoint, but most FFs it's just human and pseudo human races, even more so than XI/XIV.

And all things end. It's inevitable. Trying to insist on constant uptime isn't realistic. So XIV will end. XI has ended. I would say that WoW, even with new content, has basically ended, as have numerous other MMOs.