If copyright does not protect AI-generated content, then AI should not be restricted from generating content that falls under copyright protection; yet, the reality is otherwise.

That’s not how that would work at all. The copyright of a derivative work has no effect on the existing copyright of an underlying work.

If you record yourself reading a book, you own the audio recording copyright but it would be a copyright violation to reproduce that copy without a license for the underlying rights.

In this situation:

If the AI generates the audio recording of a book, no one owns the copyright of the audio recording but it would still be a copyright violation to reproduce that copy without the underlying rights.

I'm not sure that logic holds. If I create a frame for frame copy of Star Wars then I cannot copyright it. However, that doesn't mean that I can still distribute my copy.

These two things that are quite distinct. Whether something is protected by copyright, it should not be counterfeiting regardless.

> If copyright does not protect AI-generated content, then AI should not be restricted from generating content that falls under copyright protection

What in the world makes you think that?

What is this implication based upon? Where does it say in copyright law that if no copyright arises for your work then it does not infringe the copyright holders' rights? This is completely devoid of logic...