Who knows..sasuke has the eyes, while naruto has the body it can honestly go either way, even though imo it makes more sense for naruto to have the rinnegan since he knows much more about it than sasuke plus naruto wouldn't have to go through all the trouble of obtaining senju dna to make him stronger in order to handle it(hence hes already senju related) , but at the same time it also makes sense for sasuke to have the rinnegan because at this point i can't see him holding a candle to naruto when they fight without it, plus it will kinda edge their powers out a bit and make it a good fight.
P.S thats IF either one of them can awaken before they become old men and die