If Naruto can't be sealed, Because of his human soul, Then wouldn't that mean he can't be sealed into the Gedo Maza statue? If I'm right that basically brings the Akatsuki's ambitions to a screeching halt. I have no doubts that Obito, Zetsu and Nagato And by extension Madara will not be happy about that. Though, they possibly don't need the whole biju, So maybe the Kyuubi chakra sealed elsewhere as a substitute might suffice. But with it being a FanFic, The author can make up whatever rules they like for the story.
