I don’t care what you think of Apple, E2EE is just good for consumers. I wouldn’t send banking information to someone over SMS, but Encrypted RCS / iMessage? Sure.
It’s not about hiding from the law, it’s about hiding from those who break the law.
This just seems like another element an ad blocker could block.
It definitely depends on how they implement it. If they implement it server-side, it’ll probably work, but what’s stopping you from viewing YouTube signed out? IPs change frequently, cookies can be cleared, etc.