> someone can still come forward and present the evidence that secures them the copyright until the end of its term You mean with the current copyright regime,

> someone can still come forward and present the evidence that secures them the copyright until the end of its term You mean with the current copyright regime, whoever manages to produce good enough forged evidence, can collect on this forever? Because it's well known that copyright no longer expires. And that means there's no end of term either.