The Emperor wasn't mythological figure because he could wear the Amulet but he could wear the Amulet because he was mythological figure so I think that the absence of Amulet doesn't change anything.
Or maybe an interaction wielder/item. With the item gone the wielder doesn?t have the same significance.
Plus, if The Emperor figure has the same relevance after the events at the end of the 3rd era, then what?s so interesting about the changes those events brought?
I mean, it would be pretty boring if no significant change took place on Tamriel after the Oblivion Crisis. Yeah, yeah the Septims are gone, but what are the repercusions? The Empire goes with business as usual? The Provinces dont take advantage of the situation?