I think it's too early to determine what the maps will become. As of now, most people are just flocking to the Grounds- I think everyone is just excited about the update and go to the easiest place to hang out and socialize. But because of this, I can definitely see it becoming something akin to the old Bonfire Island.
As for the rest of the maps, they're all very detailed and interesting, as well as easy to access, so I doubt they'll become vacant like a lot of the older FH maps were. Because of this, I think the usage of these maps will be a bit different, and I don't think we'll have very many defined equivalencies between the old and new.
But of course, we'll kind of have to wait to see how things evolve over time.