Can a family organizer change their Media Apple ID and still have Apple Music access?

I was able to get this to work. I wrote it up in two related blog posts. They don't have a lot of detail but perhaps some useful clues.

The second post references the first so I'll just share that one:

https://tech.kateva.org/2022/11/migrating-from-apple-storeitunes-shared.html

Incidentally I debated between making this change now or waiting 3 weeks and doing it the day after our Apple Music family plan expires. Given the complexity of Apple ID management and of family sharing I wanted to let the plan lapse.

However a Discussion response says Playlists built from Apple Music content will be lost and not restored. So I may have to try overlapping: If I cancel my Apple Music subscription w… - Apple Community

Ok, now this thread says the Apple retains playlist and other information for 30 days. Playlist and preferences after Cancelled … - Apple Community

I can't find any Apple documentation this however, in fact I couldn't find anything from Apple about what happens after canceling an Apple Music subscription.

If the data is retained for 30 days then I won't do an overlap. But there's no way to know for sure ...

Thanks! You wrote "cancel an AM subscription and then restart it on the same Apple ID". From my experiments content formerly from iTunes is tied to the Media Apple ID, whereas family sharing is tied to the Organizer's iCloud Apple ID. Fun, eh?

For most of my family their Media Apple IDs won't change, so this undocumented 30 day rule should help them. I think they'll be ok.

I however, will have a "new" Media Apple ID so I expect the Apple Music Playlists will disappear on those devices. HOWEVER (cough) our legacy 15yo shared Media Apple ID is shared by a 'user' who has the same ID for their iCloud ID (and that was a nightmare -- https://tech.kateva.org/2022/03/what-happens-when-you-have-apple-id.html). So I have already shared URLs for those Playlists and they should still exist when I re-add Apple Music to the same ID as used by the Family Organizer.

I give it a 65% chance of working. I have no idea what happens in this morass if I were to overlap Apple Music subscriptions so I'm leaning to letting it lapse and doing a recovery. I'll also export the most important playlists from Music.app. Save a copy of a playlist in Music on Mac - Apple Support

Yes, I know all about the grief. The problem now is migrating away from the practice of 2010. Before family sharing that's how things worked.

I was able to answer my own question. The answers are:

1. It won't work. When a user is a family organizer and they initiate an Apple Music subscription from a device with distinct iCloud and Media Apple IDs they cannot change their Apple Music ID without losing access to the Apple Music. (It's not known if other family members are impacted).
2. The workaround is to wait until the Apple Music subscription expires. For good luck give it one day extra so there's no Apple Music for the family. NOW remove the custom Media Apple ID and return to the default. THEN subscribe to Apple Music for family. At this point, on that device, the Family Organizer iCloud Apple ID and Media Apple ID will be the same. I'm betting Apple Music will work for all then.