Moving families

Did you lose Apple Music playlists as a result of this?

Did you have your own personal subscription?

This is going to get to be a lot of work explaining… If you are part of a family group it is possible for one person to subscribe to Apple Music (or Apple One which includes Apple Music) at a family level. That means that other people in the family do not need to subscribe. They can share the subscription. If one of them wishes to leave the family (willingly or not), though, they will no longer be covered and will lose everything associated with the subscription. If they eventually join another family where somebody has a subscription they will be covered by that, but still there's those few seconds or minutes or days before that happens when they are not covered. In order to not lose their playlists they have to have an individual level subscription to bridge that interval. They take that out before they keave the first family and can cancel it after they join the second family (as long as somebody in that second family can cover them). In other words there isn't even a second of time when that person is not covered by a subscription.

So maybe you need to explain the situation in more details because I am apparently not picking up on your particular situation.

You might. In the legal documents: Legal - Apple Media Services - Apple you will find, "When your Paid Subscription to any Service ends, you will lose access to any functionality or Content of that Service that requires a Paid Subscription."

I interpret that to mean that anybody who does not have an individual subscription when they leave your family group will temporarily be without a subscription before they are part of the new family. They will each need an individual subscription until somebody in the new family has a family level subscription.