Youtube has to listen to the RIAA's demands because music and music videos are a huge portion of their traffic. The music industry could decide to move all that to Spotify if they chose.
They took that poison pill already, I really, really doubt they ever new pop music stops being part of youtube in the future, the audience is too large. It would be like them taking music off of the radio because people could record it on reel-to-reels. They might stomp around a bit and try to use the law to get what they want, but when push comes to shove the big labels will keep their music on youtube.
