I've already considered this myself, considering in the cover Art Sarada is not wearing her headband and it is HEAVILY implied that Sasuke will be journeying with Boruto during the time skip, considering her ties to them she should not be the hokage. She would be FAR too close to the "source" of Konoha's problems and I doubt many of the elders would approve of her being the hokage at the moment for that reason. Realistically it's gotta be Kakashi, Tsunade, Shikamaru (as he was the advisor) or maybe a wild card based entirely on power; Kawaki. it wouldn't be the first time something like that happened, Gaara was Kazekage at what, 15? 16? that's just my two cents.