What you mean is that someone can't passively waive their rights in (most parts of) the EU. When copyright expires, the work is pretty public domain. And the EU recognises public domain from other jurisdiction. It also perfectly allows someone to license a work however they like, while retaining that copyright. Regardless of how a creator allows a work to be used, the work is still their work.
AI bots never had rights to waive. Their work is not their work.
Public domain absolutely exists in the EU.
What you mean is that someone can't passively waive their rights in (most parts of) the EU. When copyright expires, the work is pretty public domain. And the EU recognises public domain from other jurisdiction. It also perfectly allows someone to license a work however they like, while retaining that copyright. Regardless of how a creator allows a work to be used, the work is still their work.
AI bots never had rights to waive. Their work is not their work.