“I'm basically giving myself a permanent vacation from being BDFL”

Sorry, but I don't see how it is his responsibility to choose a successor or create leaders. There are obviously a lot of devs on the project who were resistant to his direction, which contributed to his exhaustion.

I think it's great that he's telling them to figure it out themselves without his input. It's exactly what is needed, since it is likely to reveal the fissures more clearly. It's a lot easier to bitch than it is to lead; maybe some of them will discover that in a way they hadn't anticipated. Hopefully they figure it out before it implodes or fractures, but if not, there's a future that can handle that as well.