Dear Enno G.
Welcome to the Microsoft Community, we are glad to assist you.
We understand that you are trying to inquire about Loop workspace with no owner.
It is important to explain that no owner means that this workspace will lose editing privileges. Administrators will not be able to delete from this workspace, nor will they be able to assign members to the no owner workspace.
Equivalently, the no-owner workspace exists independently and cannot be changed in any subsequent way.
You can refer to this link for more information:
Overview of Loop workspaces storage and permissions | Microsoft Learn
We hope that the above information has been helpful to you. Please feel free to reply if you need further assistance.
Thank you for your understanding and patience and I look forward to hearing from you.
Best Regard
Tracy | Microsoft Community Support Specialist