I used Spotify with my Facebook account. When I deactivated the FB account and logged into Spotify, it reactivated the FB account automatically.
I had to create another standalone Spotify account and contact their support to migrate everything from the FB connected account to the new one, otherwise it would keep reactivating the FB account.
Just wait until eventually someone over the XDA forums creates an Android Go based ROM with those features back, but still with the more efficient kernel and base system.
I'm actually pretty stoked for this to be honest! Can you imagine if there was the possibility of switching those profiles in real-time, like an upgraded version of the "battery saver" that already exists.
I had to create another standalone Spotify account and contact their support to migrate everything from the FB connected account to the new one, otherwise it would keep reactivating the FB account.