Here is a tasty tidbit from the interview that just recently came out.:
"They will appear in the game," said Nomura of the Disney family, "but in a slightly different form. KH is generally a story where you set out on a journey with a goal in mind. However, Roxus is a member of Organization XIII, so he always returns to the home base. So, this is not a story about a journey. Also, Roxus's personality is such that he does not actively attempt to come into contact with other characters. So, the relationship to Disney characters will be different from before."
I'm guessing that Roxas couldn't give a shit about any of the Disney characters. I'm guessing Roxas would just want to fight everyone. I always believed that he got along with everyone in the Organization, but everyone else? It's hard to say with him, but Roxas struck me as the sort who fights because that is what he does. Kind of like Axel, only even more vicious.
He's meeeeeeean! Not like Axel though.