For those wondering, most of the music isn't by Yoko Shimomura. Just like FFXV there's two other composers involved, and it seems unlike FFXV, they did the bulk of the game. This is apparent with boss themes and other variants.
Most of the new songs are him and older songs from Yoko are arranged done by Takeharu Ishimoto. He's quite good, he's responsible for all the Dissidia games, Type-0, and TWEWY. For example, the main boss theme is Ishimoto, the one at the end of every Disney world\special battles and I think it's very good. Especially considering this game has little to no new music, so it's a refreshing new song.
I'm pretty sure the final boss theme is by him too among many other themes. Yoko did most of FFXV but it doesn't seem like she did most of KH3. Seems she did mostly the field themes for the all the Disney worlds and the battle themes for them. I wonder if it was because she was exhausted from working and putting all her effort on a mainline FF back to back then going into KH3.