An old theory turned radical idea I had was for Snoke to claim to be Palpatine reborn, establishing the old villian once again as the big bad of the galaxy.
However, it would later be revealed that Snoke was actually an imposter who simply used the idea of Palpatine to gain power. He really has no force powers at all, like the wizard of oz. That would retain Vader’s sacrifice while Palpatine’s presence is felt throughout the saga.