So there's a view that a rational entity should never change its values. If we accept that, then any entity with different values from present-me seems to be in some sense not a "natural successor" of present-me, even if it remembers being me and shares all my values. There seems to be a qualitative distinction between an entity like that and upload-me, even if there are several branching upload-mes that have undergone various experiences and would no doubt have different views on concrete issues than present-me.

But that's just an intuition, and I don't know whether it can be made rigorous.