It wouldn’t be able to meaningfully distinguish 4’33" from silence though.

Nor could a human though, no? There’s obviously a lot of metadata about 4’33" that makes it what it is - namely that it is a published work that is performed - but an actual recording of it is silence, so I’m not really sure what this apparent limitation that you’re talking about really is.

Edit: and an AI could observe and analyze that metadata just as much as a human could, provided it has access to it.