Your right. But my bet is still on t NOT be Xemnas or Xehanort. Simply because time travel does not exist in KH. And don't even bring up Timeless River.
Who said the battle was canon? Lingering Sentiment wasn't canon. I never said anything about this fight being canon I only said it would foreshadow the next game (probably KH3) like Lingering Sentiment foreshadowed BBS.