Keaton returning as Batman would be good for marketing (imagine the crowd going crazy at Comic-Con for the reveal trailer) and can totally work >>>>>>> depending on the script and the person who directs it. WB dropped the ball when it came to developing scripts (for DCU), hiring legitimately good directors, and allowing those directors to craft a compelling movie.
I'm more optimistic about Matt Reeves than an previous directors (since Nolan), however Hollywood is off-track these days. They're more preoccupied with pandering than entertaining.