Do you really think that Master Xehanort can actually predict what will happen 10 years after his demise in BBS? Him, turning into a Heartless and Nobody and coming back whole again with other versions of himself. I'm thinking, someone else is controlling the puppet master. Maybe one of the Foretellers from KHX or a reincarnation of them could be a part of this. Maybe Master Xehanort is trying to start the Keyblade War not only to get Kingdom Hearts appear but to summon the Foretellers.