In my experience, virtually no one goes of their own volition. Generally dragged kicking and screaming by family, friends, or employers. it is not without feeling a sense of shame. I've been in rehab.. It's not what I would term as a happy place.
I wish the best for Keim personally whatever the reason. I, too, don't want him to return to his duties.
That being said, Elon Musk would make a fine interim GM. He'd get rid of everything including the expresso machine.