I feel like this game is loading up on KH Foreteller stuff which doesn't seem to have any connection to Yozora/Quadratum.
How Quadratum works and the people within is deliberately kept from us. We'll learn all that relevant information in 4 itself, since no one in the KH side of that universe knows anything about it. I don't see why it would make sense to learn about Unreality that early too.
Xehanort should learn about Unreality, yes, but it wasn't something he had much of a grasp on based on ApprenticeNort's speech in Melody of Memory so learning about it might be chalked up to one of his conversations with the Master of Masters. But if he's there in Quadratum as theorised, then that's something for 4 to address, not Dark Road.
The Foretellers Arc should transcend Quadratum, so I understand that Nomura is using the time he has before overloading us with Unreality stuff to hash out some important details about the darknesses and the Foretellers.
How Quadratum connects to the Master of Masters and the darknesses is clearly a plotline to be explored in 4 itself.
It also introduced so many new characters and didn't give them enough time to be fleshed out. Unlike the Xion situation, she was just one character and had a whole game focused on her. Dark Road had many characters introduced then killed off just to maintain continuity.
We almost didn't get the Upperclassmen. Nomura cut so much out, including them, but then decided to put them back in. I imagine that was cause for the big delay in Dark Road's release.
But I also feel like I'm the only one who was okay with not delving into the characters of the Upperclassmen. I liked that they individually have some mystery about them. I don't need to know a lot of in-depth details about them. They believed in a mission and were fighting for that cause and it was their undoing. The existed to move the story forward, and sometimes that's okay.
We might see them again in the future and they can be fleshed out, or they might not. Dark Road was a victim of budget and scale and I'm impressed with what they pulled off, ultimately.
but the real question I have to ask here is why? The Dark Seeker Saga is over. Dark Road should have shown Xehanort's past, but also build up lore for KH4. Clearly Ansem/Xehanort knew of Quadratum, Dark Road should have shown how he got that knowledge and maybe went further into details about Quadratum.
It more set up Missing-Link than KH4. The concept of Bloodlines, which is a central theme in Missing-Link, continuing the Players journey, as well as Brain, Not-Skuld-Real-Xehanorts-Mum, Odin, and Sigurd, then there's the child of destiny prophecy which we might see the beginning of in Missing-Link.
KH is exploring two different central storylines at the moment that should
intersect somewhere in a future game. It's kind of like Marvel making some of their properties focus on Multiverse and others just a generic super hero journey, and then it merges together into the Avengers films. I think of KH like the mobile games tie in to the next mobile game, the console games tie in to the next console game, and then they will intersect (which is what is happening with Missing-Link and 4)
We know parts of Missing-Link will be relevant in 4 (especially Sigurd if his voicing both trailers means he has a part in 4 itself) and Mickey is investigating Scala. Once Sora is free from Quadratum, with the knowledge of that side of reality and all it brings, then it might tie all in together with the legacy of the Keyblade Wielders.
Don't forget Nomura's closing statement during the Gameinformer interview
I also wanted to mention Kingdom Hearts Missing-Link
. We're working towards launching the closed beta within the year. I know that not everybody is really into smartphone games, so some fans might not be really excited for it, but we are making it so that it's something that anyone can jump right into. Compared to our past mobile releases, it's a lot closer to the series and also connected in many ways to Kingdom Hearts IV.
The easiest way to get more new information and hints about Kingdom Hearts IV would be first to play Missing-Link. There will also be some more mysteries, not related to Kingdom Hearts IV specifically, but just throughout the series in it. Also, some figures that appear in Missing-Link are tied to Kingdom Hearts IV.
Dark Road served its purpose on getting Xehanort's character in line for KH4, as well as getting the concept of Bloodlines and heritage ready, and introducing us to Odin and concepts like the Darknesses which should be explored in Missing-Link, which in turn will go to KH4. If some questions about Quadratum aren't answered in Missing-Link, then there's a reason for that.