So I beat the game last night and as much as I loved the game ( especially the end game like phew that was everything I wanted) it felt like it was missing something. Seeing as Nomura isn't against DLC and said he would do it in one deep package I'm assuming it'll be in a Final mix type Version. So if that was to come this is what I think should be included or at least addressed.
Spoiler Showincluded: The adventure Sora takes to save Kairi. I understand why he vanished as that was his price to pay but I would like to know where he went to get her like maybe Sora going through the realm of darkness to get her. Maybe he used that Trump car Luxord gave him to save her.
A handful of secret bosses or a similar version of the Data Org battles. A lot of people we're saying that the main games always included a secret boss that hinted at the next installment but that's only slightly true as it was the final mix versions that added the super OP boss. I'm sure it'll either be Yozora or MoM. Definitely will be in a black coat lol.
I'm sure if they do make a final mix they'll extend the secret ending showing off more maybe even a fight between Riku and Yozora or Sora and MoM.