It’s not clear what type of content users are seeing as they scroll, is it video or playlist? There’s little visual difference to help users to tell them apart. There’s also no clear affordance how to interact with the content. Should users tap anywhere on the screen or do they have to tap on the play icon? Another usability issue is that it's not clear which direction the content scrolls, or whether it's scrollable at all.
Another problem is that this navigation pattern provides very limited ways to consume content. Music videos are relatively well structured content, they can be organized by Artist, Genre, Time and sometimes even album, but the old design only presents content as either video or playlist.
Finally, with this design is that the chance of recommender system making an accurate recommendation is lower because there's only one item per screen.