[meowface]

YouTube isn't the one sending these takedown notices. People send the takedown notices to YouTube, and then they take required action afterwards.

Presumably, people who signed an agreement would not send takedown requests. As you mention, there are cases where this does sometimes mistakenly happen, like if someone is being represented by some agency or firm and they don't realize the content is part of the agreement, but it should be disputable in those cases, and usually will get resolved.

(It's true that sometimes it takes too long for those cases to get properly resolved, but that's a separate thing. I'm definitely not saying IP management on YouTube is perfect - there's plenty of abuse and errors in the copyright system. This just isn't one of those situations.)