YouTube Music is receiving an update with lot of new features and one of the biggest is allowing the streaming when you are connected to WiFi only. You can enable this features by heading to the settings of the app.
If you guys are not familiar with the YouTube Music app than for your information, it is the app made for YouTube Red subscribers. You can now choose to stream music videos only in WiFi and that too you can choose from whether you want to Stream HD videos or not (it is old feature).
Other addition is the “More button(artist)”, which will give access to whole music from that particular artist.
Other changes are also present but you can experience all the advancements by heading to the Play Store.