Reason Orochimaru was Revived And Madara's Fate
You know this whole Birth of a New Era Project or Part 3 as some are calling it, creates an interesting possibility:
Maybe the reason Kishi revived Orochimaru was because he would be involved in this part 3, and Madara make turn out to still be alive after Kaguya is defeated.
Maybe the reason Kakashi becomes Hokage is because Orochimaru and Madara both disappear after the battle and Naruto and Sasuke decide to go after them to deal with them, Naruto can't sit behind a desk while those two are running around causing trouble.
It doesn't make sense that Kishi just revived Oro to act as a commentator and stand around during the battles, and Madara may yet play a part in Part 3.
Or maybe Madara is left vastly weakened after Kaguya is defeated and Orochimaru seizes this moment and takes over his body, but has to run away because he realizes that even with Madara's power he can't beat Naruto and Sasuke at the moment.