Oh so that's what he meant.I believe what he means is that, Sasuke will see Naruto battle Obito (Presumably with the Whole Bijuu chakra advantage) with all his power. This means Sasuke will have first hand intel on Naruto's final abilities. That in tandem with Sasuke's Perfect Susano'o and possible new EMS tech will allow Sasuke to beat Naruto. I understand what he's saying, but obviously the end product is... Naruto > Sasuke.
But that would work the other way around too, Naruto is seeing Sasuke fight as well so it goes both ways.