I think there’s a third scenario where the copyright holder ‘claims’ the video - it remains monetised, but the money goes to the copyright holder. Not sure if that still happens, it did work like that in the past - because there were cases where it was abused by the copyright holders to claim against fair use and falsely-matched content.
Yes, that’s a common one as well. I just grouped it in with ‘demonitzed’ since, to the uploader, it’s the same thing (they either get money or they don’t) and I was trying to keep that part a bit simpler.
I remember a case where a gaming Youtuber received a copyright strike because he hummed part of a song. He was playing a Call of Duty game on a map called Miami and he started the video off humming “Oh na nana nah”. That was enough for a copyright strike. As I recall, the claim came from a group representing the music rights for Central/South America where I take it this kind of copyright infringement is looked upon particularly harshly.