Interesting...
It looked like UMG had made a strategic mistake in issuing takedown requests for content they didn't own, but this could potentially be a win for them on a much larger stage.
If, as they claim, their contract with Youtube gives them the right to take down content they have no rights for, and that contract will necessarily be revealed in discovery, then Google comes out of this the biggest loser by far. UMG gets off scot-free in the Mega case and Google loses the trust of users and content creators. I wouldn't be surprised if the content industry views anything that hurts Google at this point as a win for them.