That's not true because you send or receive data from other peers only if you are already watching a video. In other words - p2p is used only in places where the data would have gotten from the server anyways (e.g. p2p didn't add any new users to the equation)

I'm not sure what's your point.

You A are getting content from server S. B is getting the same content from server S.

With this CDN, what changes is that A is now sending content to B. Content that may be illegal. The fact that would mean A was accessing illegal content doesn't change the fact that this CDN moves him from a downloader to an uploader, without his content nor telling him, something that has legal precedent for leading to convictions in europe.