YouTube could be subjected to a class action in theory not in practice, because the terms of the site are so loose you can get ejected with no recourse and lose

YouTube could be subjected to a class action in theory not in practice, because the terms of the site are so loose you can get ejected with no recourse and lose wages, while indemnifying them. UMG however has not any relationship with the author so they actually can be sued. If they hate their subcontractor YouTube for it, that's their problem. They're the legal entity on behalf of which blocking is done, after all.