Okay highly unlikely for plot reasons but I couldn't help myself. Assuming that Naruto isn't able to replace whole arms via his holy powers, wouldn't it be interesting for SZ to replace their lost arms with mokuton the same way Madara did it with a fodder white zetsu?
In all the previous fights between reincarnations, either Black Zetsu or Black and white Zetsu as whole, would watch over the transmigrants. Now however, that they're gone, wouldn't be interesting to see the bad guy (SZ) to offer help and mostl importantly a power- up (mokuton arms) to his opponents, hoping to exploit them in some way in the future?
In all the previous fights between reincarnations, either Black Zetsu or Black and white Zetsu as whole, would watch over the transmigrants. Now however, that they're gone, wouldn't be interesting to see the bad guy (SZ) to offer help and mostl importantly a power- up (mokuton arms) to his opponents, hoping to exploit them in some way in the future?