but after copyright expiration
I’m not at all convinced this is ever going to happen, and currently have no reason to believe it ever will.
While I agree copyright extensions are already to ludicrous levels and may get worse, never is a very long time. It’s just my opinion, but I think they’ll give up before they hit 10,000 years. Also, the fact that copyright terms are codified into so many multilateral trade agreements actually makes further extensions a lot more complicated than they were only a decade or so ago. Not impossible, but certainly more expensive.