if sasuke still felt the hatred he did then it would be a final fight but that is over with now... WHY would kishi have sasuke and Naruto repeat the same mistakes as friends that Madara and hasi made in the past? what was the point of the flashbacks if sasuke was just gonna be just like madara lol.
That's why something really bad is going to happen probably. No other reason for them to fight unless Sasuke decides to help in the war for Itachi's sake, then decideds to try and kill Naruto after it's over. Either Kishimoto wrote himself into a corner after planning the ending at the start or he's got big plans.