Possibly the Black Zetsu will betray Madara.
Black Zetsu was made from Madara Himself,from Madara's own will.Not likely to betray Himself.
It's the only way I can think of a fight actually taking place, since Sakura has barely any chakra and Obito is trying to stop BZ. If the caption at the end hinted a fight, it's all I can think of logically with the current situation, unless Sasuke somehow manages kamui.
Well, that is the only way if Sasuke or Naruto have a way to get their. Yet take into account Kishi did say a Major character will die and Naruto and Sasuke have survived their near death experience and powered up. So don't count out either Sakura dying or getting so beat up that the seal barley keeps Her alive but Her Ninja career in the field might be over. Sines Tsunade and the Kages nearly died,Shikamaru nearly died.Kakashi for a time almost did. Sai too leaving Sakura as the only one on team seven to be in a life and death situation in the war. Very complex.