I think it would be cool if Yozora wasn’t the final boss. I do think however that we will play as Sora. The secret boss of a game is supposed to be where you use all of the skills and techniques to their max. Since we barely play as the other characters and their load out is prefixed I don’t think we’d be able to have a good secret boss. It would have to be nerfed from something Sora could take on. Just my 2 cents ?♂️ It would be cool if they could make it work though, don’t get me wrong!