The pause button make sense, force users to focus on the page briefly every now and then to save bandwidth - Netflix does something similar to prevent long running auto-play.

The looping is quite different though, there's no legitimate use for it, and I can't find any controls that would allow you to set a song to auto-repeat. So it's either a bug that they're struggling to fix or an intentional change to make play-lists less functional when you are not watching the platform.