I'm going to go out on a limb and guess that he knows the Christopher Reeve version of Superman and only that version. I really think they are just going to try and copy the MCU--so we will get the Chris Evans version of Superman and the Thor version of Aquaman, etc.
The DCEU has its own, strong voice and should not--under any circumstances--copy the MCU, including Chris Evans, who presented a character that was the polar opposite of what Superman was intended to be (which was not the oft-abused, misapplied "boy scout" description). As established, he (Superman) was coming into his own / dealing with trying to fit into humanity (which is how the character should be handled, not having him winking and grinning as if he was your Daddy/camp counselor).
Further, Singer already tried to resurrect the Donner version, copying characterization beat for beat and it was a dreary failure. The world has moved on from Reeve and is not looking back, just as in 1989, no one was looking back for a revival of West's Batman.
Dwayne Johnson was right on point when he said Cavill's version is
the Superman of this generation (and its certainly not whatever 1978 throwback bumbler act Hoechlin is using on the anything-but-
Superman and Lois).
I was never a fan of Keaton's Batman or Burton's Batman for that matter.
Same here.
But it would have been cool to see Keaton in a few films before passing the torch to a Dick Grayson actor. Grant Morrison's Dick Grayson Batman was a great character and it is a shame that DC didn't turn Bruce Wayne into the 21st century Barry Allen.
Keaton is supposed to be in a different universe / reality, so he--and any would-be successors end up having little impact on the main DCEU films. Like Silver Age Earth II stories, they exist, but were not the main driver of the universe.. As noted yesterday, Keaton would be served best if he takes up the costume for one, last time, leading to his death, and some sense of satisfaction that his work meant something, which does not necessarily mean passing his Bat I.D. to another.