I was just thinking recently, the beggining of Limit Cut stated that a bunch of the cast are off in their own adventures.
Terra, Ventus and Aqua are on the Realm of Darkness, the Twilight Town gang are searching Ansem's data, Kairi is sleeping while the apprentices are searching her heart and Mickey, Donald and Goofy are going through the worlds they visited looking for clues.
While a lot of those could be nothing, a few of those could be spin-offs on their own.
And then I remembered this:
Kingdom Hearts Insider - the largest kingdom hearts community and news resource on the web!
www.khinsider.com
Scholastic is releasing a Kingdom Hearts middlegrade novel series sometime this year, and they make sure to call it "official" and "canon" as much as they can in these (Now deleted, mind you) Amazon descriptions that I might even believe they're serious.
What if the story of these books were one the aforementioned groups looking for Sora? The placeholders for the books first showed up August last year and Re:Mind was announced in April, and was probably in production for longer than that. Maybe they actually planned a collaboration for these books.
The easiest thing would be the Disney trio going after Sora, since they are the least developed Kingdom Hearts characters, but the most recognizable Disney ones, they don't really have any baggage after 9 games, so there's no need to waste time introducing them. The concept is also the most basic Kingdom Hearts plot ever: Visit Disney worlds while looking for a person they lost. And since they are the most static characters in the series, they could have an entire five books journey and still come back for KHIV without the audience having to read the books. Because let's face it, anyone but them are gonna actually rescue Sora.
It would be the most accessible way to introduce a new audience to Kingdom Hearts universe in another medium, the story wouldn't necessarily be weighed down by all the lore in the game, but it could still be acknowledged and referenced in a need-to-know basis to suit the story's need.
But that's only IF the story's actually canon, they could just as well be using that buzzword for marketing purposes.