YouTube Music, the newest music streaming service from Google, has for a long time been an option for US users to have as their default music option. This was true of the old version of the service as well as the new one. Now those of you in the UK have the same option to make YouTube Music your default music choice.
The update to enable the feature is a cloud-side update and will appear as an option in your music settings within Google Assistant. Once enabled, you can say, “Hey Google, play Rush from YouTube Music” and it will play music from Canadian band on your Google Home device.