How exactly is this a nerf?
Sasuke needs time, training and experience in order to gain these abilities that kurama says he doesn't have right now. By your logic, kid naruto was nerfed because given enough time, training and experience, he would have been able to use oodama/ chou oodama rasengan, fuuton rasengan, and the rasenshuriken.
Nerfing is if sasuke had the ability to do something before, and kishi now takes that ability away. Sasuke simply never had the ability to use preta path while using ninjutsu so it's not a nerf.