Pretty sure I already posted this a while back in some other topic but may as well do so again.
For starters, I probably wouldn't even get a Days FM because I don't think going through that story once more would be worth it. Unless they changed it (lol) but that would never happen.
As far as likelihood goes, well, every title to date aside from Days has been modified and/or given additions, so I wouldn't rule it out. Wouldn't surprise me if they create it to tide us over as part of Nomura's promise to release a game each year.
What I would like to see:
- Different playable character costumes. Use final form Xemnas, KH2 Sora (and perhaps his drives), KH2 Roxas (maybe Ven as well just for kicks), KH1/KH2/Dark Mode Riku, normal clothes Goofy/Donald, maybe Lea, Isa, and the apprentices as well. On that note, have some additional playable characters (Xehanort's Heartless? KH2 Kairi? I'd ask for Terra and Aqua too but I'd feel like that would detract from BbS).
- Way more original Heartless. Not palette swaps but completely new ones. Tired of seeing ten variations of the same Heartless.
- Way more Nobodies to fight in those arena modes (in the Hall of Empty Melodies). This includes old Nobodies as well as new ones to represent the CoM members.
- New attacks, naturally. I'd like a mode where Roxas could summon Samurai Nobodies, as this was originally supposed to be implemented, but left out.
- I'm actually ok as far as weapons go, I think we have enough as it is (given all the playable characters and each of their variations). The only kind of additions I'd like to see here would be, say, Roxas using Sora/Ven keyblades.
- Pinocchio's world, playable Destiny Islands (seriously, they had missions there, yet we never played there? C'mon), expanded TWTNW hub.
- A mode where you can fight the Org members a la Data fights. I know this was KH2FM's forte, but I'd rather be fighting the same Org members again than just Heartless constantly. I would ask for other non-Heartless bosses (Gaston, the other titans, etc.), but I know that wouldn't happen since they'd have to change the story.
- Detailed "Xemnas Reports" (with pictures) on the original names, lives, and deaths of the members- including Xion so they can actually confirm that, yes, she was created from the memories Xemnas sampled when he fought Sora.
- A poo ton more connections to BbS. There'd be no excuse now about being so secretive. They should delve into the Chamber of Waking, analyze Roxas' relation to Ven, as well as Xemnas' relation to MX and Terra, for starters.