It makes perfect sense when you think about it, Sasuke revealed in the latest chapter that this whole time he was waiting for all the threats to his Revolution to be eliminated. Madara, Kaguya, Obito, Black Zetsu, the edo Kage, and double kamui Kakashi mainly and now Naruto is the only one left. During the fight with Kaguya, Sasuke stated that he or Naruto couldn't die because they had to seal her, so he cooperated, but in the back of his mind he knew his true goal was to take out Naruto. Sasuke did next to nothing against Kaguya because he was preserving chakra and letting Naruto do most of the fighting. Sasuke's not dumb he realized early on that his rinnegan eye and Kaguya's would simply cancel eachother out, so Naruto was better suited to fight her. Now that Kaguya has been sealed and the other threats removed, Sasuke is relatively fresh while Naruto has exhausted most of his chakra and the bijuu are locked away in Chibaku Tensei so they can't leech him more. I personally would like them not to fight now, because logically Sasuke would win easily at this point. I want them both at their best.