If that happened, Obito would have turned into a tree long time ago, since he's made of Zetsu. (Remember Obito used Izanagi because he had Hasirama's chells too, like Madara).
If you were right, then something like that would have already happened in the last chapter. Remember how close Naruto was to Madara? The scene where he threw his Bijuu-dama onto Madara's Gunbai.