Does Musi have a special arrangement with YouTube?

I wonder how Musi, a music app that has consistently been ranked as one of the top 10 music apps in the US, outranking Google Music and the likes, is still on the App Store pushing updates, and even made a recent appearance on the Canadian version of Shark Tank (Dragon's Den) trying to raise money. I really think it's a cool app, but Youtube API Terms prohibit separating audio from the video and since they launched Youtube Red they've been giving developers notices to remove this feature or potentially face legal actions. How come Musi is not being targeted with this? Do they have a special agreement? On the same subject, Youtube should really make background play a free feature and allow developers to implement it. They could require the video to stay in view within the app so they can serve their video ads, and let the audio run when users exit the app or turn off the screen on iOS, since it's not currently possible to serve videos in these cases. There is nothing to watch on most Youtube music videos anyway, and I'm sure that Youtube with all its might and power can convince copyright holders to accept that it's good for them too, as they can monetize this feature with audio ads. It's one of the main complaint with the official Youtube app, so that would help them too, and it wouldn't prevent people from switching to Youtube Red or Spotify, as audio ads are pretty annoying. So really Youtube, make background play a free feature and level the playing field!