i dont see anyone getting it, it would be pointless...naruto's character type sticks to the power he can attain through work and perseverance so rinnegan totally goes against all that. And even if sasuke got it so what? getting the rinnegan wouldnt mean sasuke could use the paths anytime soon he would have to go off and train to learn them. Nagato didnt know the techs from the start, otherwise what stopped him from reviving his friend(i forget the name) when he was killed by that hit squad? or using almighty push in anger against them? Konan said the revival jutsu would kill him due to chakra consumption, so one life should have been nothing even for a young nagato. There would be no reason to assume sasuke would instead know everything instantly as opposed to going and learning it all. That said, all that would happen is sasuke would get another big chakra boost, perhaps to around half of narutos massive chakra pool, and would keep spamming EMS techs, assuming they could be used anymore (since although you'd think a rinnegan user could use them, nagato couldnt although sharingan techs should be encompassed in the rinnegan level). If sasuke got dual rinnegan eyes, and couldnt use sharingan techs, he would be worse off then ever...however im sure kishi would write in yet another plot no jutsu to help sasuke progress to naruto's level so he could put up a fight or in the event of them teaming up against madara or gedo mazo, could be of some use.