Skeuomorphism is a design where there look of an object used for a function is copied in a tool performing the same function.
Like early electric lights where made to mimic candelabra, lemon juice is put in a container in the shape of a lemon or the ‘call’ button on a smartphone has the icon of an analog phone on it.
In the latter case there’s a word thing going on. With the telephone as with the floppy symbol on the save button, there is a point where more people have never used the depicted object. There is a certain point in time where the symbol is used longer than the actual thing.
If that’s the case, can we still call it skeuomorphic?
I think up until which point you would still call things like that skeuomorphic is entirely subjective, depends on how you want to define it. These things will always be of skeuomorphic origin, at least.
It’s a very interesting process indeed. I imagine these designs will morph over time into something else, as their original meaning does not matter anymore since no one remembers it vividly, and all that matters is them being widely known and distinctly recognizable. Just like it happens with words changing over time.