If they're going for a lighter , more comedic tone than
The Batman 2 and
Joker 2,
than a cast
could look like this
The Cast

Batman / Bruce Wayne 50 something, around the block version : Jon Hamm
Yeah , I know , but if they're going for a Batman who could do the broody stuff yet can also pull of the lightness and humor,
he could do it.

Robin / Damien Wayne : Logan Kim ( Ghostbusters : Frozen Empire )

Oracle/ Barbara Gordon : Zoey Deutch , 29 ( The Outfit)

Nightwing / Dick Grayson : Logan Lerman ( Bullet Train)

Alfred Pennyworth : Bill Nighly
Again, this is a cast that lends itself more to action -comedy , than a more serious Reeves/Nolan like take, though Nighly would make a great Alfred in either type of tone IMO.