I don't know, with the way Yozora suddenly is receiving all this attention and advertising even with the new addition of the Remind DLC I would be very surprised if we never see Yozora and his crew in KHIV or any of the side games. Much less not have some important role to play in a portion of the main story. At this rate he may star in his very own side game/spinoff in the series. It also couldn't be a total coincidence as to why the Nameless Star was there near the end of the game and why she mentions Yozora to Sora. I figure since characters like Aqua, Ven, Terra, Axel, Xion, Roxas, etc. are going to be doing their own thing in other games, Nomura wants to create new protagonists like Yozora and Nameless Star to join Sora, Riku, and Kairi in KHIV. Just a theory though.