Change Family Organizer and NOT loose purchases

Once the family is disbanded and then set up under a new organizer, if the family is the same people, everyone should still have access to a family member's purchases for sharing.

Family Sharing - Leave.          

Family Sharing.         

Family Sharing - Set up.       

If there are children under 13 years old, the new organizer needs to leave the existing family, set up the new family, and then the under 13 years old children can be transferred to the new family. Then disband the old family and join the new family.

Family Sharing -  Transfer a child to a different family group - Apple Support?        

The name on your Apple ID? Use the below to do a name change. You will retain access to your data and purchases.

Note the restrictions in the article.

Apple ID Name Change.        

 What to do after you change your Apple ID or password - Apple Support    I suggest doing this before you change your Apple ID or password.