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.