I've read that if you get three "copyright strikes" in 90 days, you can lose your account (and any channels attached to it). But a copyright strike is not the same as when a video gets flagged on upload for a content ID match, which has happened to me multiple times with zero consequences (other than potential demonetization, which for me isn't a concern at this point). When that happens, you get a message explaining that "The Content ID claim on your video doesn't affect your channel. This is not a copyright strike." I don't know if there's a limit to the number of content ID claims, but it seems much more benign than a strike.
I've also had one video blocked after upload, but that was also not a strike, it was just a more severe form of content ID claim. In that case, I had assembled a photo montage reel for a hockey team with the season's game music as a soundtrack, so it had at least 10 copyright violations in it. I really didn't expect it to pass the copyright check but hoped if I set it as unlisted, it would sneak through. Nope... it was unviewable as soon as processing finished.
For a strike to happen, the copyright owner has to actually submit a formal takedown request. It prompts
specific steps you have to take (including copyright education). At least, that's my understanding - hasn't happened to me yet.
Here's the flip side: my cousin did get a strike when he used a piece of Wikimedia Commons public domain licensed music (a piece of Chopin's Nocturne) in a video. Some musician also used that same recording in a song, and then went after him. He tried challenging it, but I don't think he won (I need to find out what happened). Point is, even with music that should be completely free to use, there are risks.
Anyway, IANAL, YMMV, etc...