For me, what I am more interested about is how they are going to fuse this story with the next phase in a coherent way. This sounds like a crazy challenge since probably 1% of the KH console user base will know about this finale.
But this barely changed the status quo of the console games, if we actually think about it. UX was pretty self-contained with it's story and there's not many consequences to the story moving further, just context added to things that already happened:
- We now know the somebodies of Marluxia and Larxene, as well as why Marluxia was so obsessed with having a Keyblade, and can even try to stretch and justify the "stand" he uses in his second phase as well as looking like Stretlitzia.
- We know how Scala came to be.
- We know how Ven ended up in the Keyblade Graveyard, why he has memory loss, the origin of Vanitas and what was the Darkness in his heart in Re:Mind as well as why Charithy says it's better if he doesn't remember them in the final world.
- A bit more context on the Dream Eaters and why they haven't returned as an enemy (which may be how the whole surfing-on-keyblades happened in kh3? If it's a reference to Sora coming back to say goodbye to his Dream Eaters, who knows?)
- We know what the Ark/Lifeboats are.
- We know exactly when and how Maleficent came back in KH2, which used to be a plothole for the longest time. And why she is after the box.
The Foretellers, the Black Box, No Name and the Master of Masters are all in Back Cover and while I don't think that movie works as a replacement for UX, it still shows just enough to understand the origin for those characters, considering we're most likely only finding out abot how they even returned in the first place (or where they had been all this time) in a new console game.
Dark Road is another story entirely, though. That one will probably have a bigger impact with Luxu's role after he started bodyhoping, the line of rulers for Scala as well as what happened to that world (and what connection it has to Land of Departure, if any), what Xehanort talked about with the Master of Masters and what happened to that piece of Darkness, what happened to the population of Keyblade wielders to thin out so much, etc.
But then again, Dark Road is MUCH shorter and streamlined compared to UX as well as being easier to adapt into a movie format or even a game remake if they desire. lol
I fair question: how common is the technology used by the "new" character in the Kh saga? To me, it felt kind of out of place.
We don't actually know what they used in the first place, but we already have smartphones in Radiant Garden at KH3, which is the world closest to the level of technology Daybreak Town and later Scala had. The feeling of it being out of place is because it was never really showed before throughout the X saga and it looks weird in sprite format, but the entire UX game took part in a data world in the first place. lol