I think any future director should steer clear of Nolanisms. I don't want direct adaptations of comic stories anyway. I appreciated how Nolan took the best from a wide range of series and distilled them into what would work for film.
Anything too esoteric wouldn't make it, and some of the stories require substantial investment before you can get to the payoffs. You should stick to the one-offs for simple movie concepts. People don't want to stray too far into the crevices of Batman stories. That said, a Gotham by Gaslight would be fine by me.
I'd lighten the mood a little bit and try for something a bit more superhero-y. Just don't do Nolan-lite. What would be the point?
If Rian Johnson were to continue this specific series with JGL, I'd be down with that. Him or Nolan aside, though...just do a reboot.
And for a reboot, I'd like Michael Mann. Why the eff not?