PeerTube doesn't even help there, it just means that innocent end users will be hit with DMCA notices. In a way it's worse than BitTorrent because at least with BT you could make some kind of argument that end users knew they were doing something illegal (even if that argument was dubious). Now you'll have people visiting a website that looks a lot like Youtube and getting DMCA notices because of some background music in a video they were watching.

(For the avoidance of doubt, I think PeerTube is great technology and I hope it wins, I just don't think it has any chance of supplanting Youtube any time soon).

Depending on the country, getting hit with a DMCA notice carries more or less weight. The ones sending the notice might also need to be very clear about what you did wrong. And a notarized letter is less easily prone to spam and abuse than a message inside YouTube's system. And you'll be probably able to win in court if the claim is spurious.

Much better than the current situation with YouTube's ContentID where the presumption of innocence is routinely violated, not to mention all the other issues : https://www.youtube.com/watch?v=trIn90HTqKs

(Also, the way the current ContentID might be violating European laws deriving from Article 13, but I haven't really been following that lately...)

Has anyone visiting PeerTube been hit with a DMCA notice? I'm curious please provide any links you have to articles.

I doubt it's popular enough for any of these parasite legal companies to bother right now. That can change if it becomes popular. No I don't have any links.