Perhaps when each world returns to the RoL they'll hold clues for each person that needs to be saved? It would be kinda lame revisiting them but it's some sort of Disney connection..
That would be a possibility indeed.
Also, when I look at the worlds and the list of tormented ones each world (loosely) corresponds to one of them, although I am probably now overthinking things.
Like the Grid (Tron: Legacy) corresponds to Ansem the Wise, he's a technical genius (created the virtual Twilight Town, hid the data inside Sora).
Symphony of Sorcery has heavy emphasis on Magic, corresponding to Aqua.
Prankster's Paradise is Pinocchio's world and Pinocchio is a "doll", corresponding to Xion who was also a "doll".
Traverse Town was/is a world comprised of parts from other worlds (see KH 1), that corresponds to Roxas, who was a being created from more than one person.
Country of the Musketeer with its "all for one, one for all"-salute and the heavy emphasis on camaraderie and friendship corresponds to Ventus, who's a big friendship-freak.
Hunchback of Notre Dame has Quasimodo, who initially is withdrawn and timid at the beginning of the original film, which correlates with the timid personality of Naminé mostly in CoM but also in KH2. Frollo is the equivalent (role-wise) to Marluxia (CoM) and DiZ (KH 2/Days) in regard to Naminé.
Since we don't know if TWTNW is really the seventh world with a keyhole of sleep I won't yet assign it as corresponding with Terra, but if it is it would also fit since Xemnas, the former ruler of TWTNW, while certainly
not Terra himself, had some of Terra's memories.