Kingdom Hearts III will have mostly New Worlds

[Andromeda]

Out of E3, Nomura and Square Enix had more to discuss in interviews about Kingdom Hearts III. They were able to talk more about the game with it further along. In his interview with Famitsu, he was able to confirm that combat will not be like that of Birth by Sleep with the deck commands returning the more establish systems used in KH1 and KH2. The free running that they add to the game will give Sora more mobility than he has had before able to jump and run over most things in the game and even run up walls. While they showed off Olympus in the trailer, he confirmed most of the worlds will be new ones like having the Tangled world.

While already stated, he reiterated that this will conclude the Dark Seeker story of Kingdom Hearts, but that does not mean an end to the franchise. He said that they have a release date already in mind, but can't talk about it just yet. He also said that they are already thinking about secret movies to put in to the game, like most Kingdom Hearts.

Source: Most Of Kingdom Hearts III’s Worlds Will Be New To The Series - Siliconera