This seems like a solution in search of a problem.
I can see how someone would think that if they've never been in that situation. Having been through two group transfers, one voluntary and one caused by the abandonment of an owner, I understand that this is something that groups.io is going to have to face, if they haven't already.
We have also heard from owners who added a second owner and were then pushed out of their own groups. I've had a similar situation where I transferred ownership of a group to another person because I didn't have the time. That person later made a new person an owner, and that person then kicked most of the original members off. Any time you're dealing with humans and bestowing authority, a lot of unexpected things can happen.
I don't know if Mark has any kind of an unwritten policy on this, or if it's something he deals with on a case-by-case basis. I can understand how he would need to be the ultimate arbitrator in strange cases, but if an owner had a way to indicate preferred succession, that might be helpful to him.
Dano
D R Stinson