James Gunn’sSupermanfeatures a clear reference to theDCU’s Batman years ahead ofThe Brave and the Bold’s release. Gunn’sSupermanintroduces seven DCU superheroes who will return in multiple upcoming projects. After recruiting Metamorpho and improving their public image,the Justice Gang seem to have a bright futureparallel to Superman. Meanwhile, Milly Alcock’s Supergirl has visited Earth to take Krypto back from her cousin.
Metahumans have been a normal part of life in the DCU for at least three hundred years, meaning that dozens of superheroes and supervillains may already have come and gone. Since Damian Wayne will already be Robin inAndy Muschietti’sThe Brave and the Bold, it’s safe to say that Batman has been active in the DCU for several years. In fact, Batman has probably been a famous vigilante much longer than David Corenswet’s Superman has been a famous superhero.

James Gunn’s Superman Has A Blink-And-You’ll-Miss-It Batman Easter Egg
Superman Confirms Gotham Is Close To Metropolis In The DCU
Once Lex Luthor’s pocket dimension portals break down and a rift threatens to destroy Metropolis, all citizens are evacuated to neighboring cities.At one point during Metropolis' evacuation, a “Gotham City” road sign can be spotted for a split second.Traditionally, Metropolis and Gotham City are located right next to each other in DC Comics, though this has only been a relevant detail in the DCEU.
A newscast covering floods inSupermanhas raised questions aboutSuperman’s potential connection to Matt Reeves’The Batman. While a connection between the two would seem likely, James Gunn and Matt Reeves have already confirmed hat Robert Pattinson will not be he DCU’s Dark Knight. Hence, the “Gotham City” road sign easter egg is the only official reference to the DCU’s Batman inSuperman.

Batman Already Appeared In The DC Universe
The DCU Is Laying The Foundations For Batman’s Proper DCU Debut
James Gunn’s DCU has officially teased Batman at least three times. BesidesSuperman’s Gotham City easter egg,the DCU’s Batman made a cameo inCreature Commandosepisode 5, where Doctor Phosphorus revealed the Dark Knight was the one who sent him to prison.Batman is also one of the heroes who appeared in Circe’s visions of the future, where he was crucified alongside other DC icons like Wonder Woman and Starfire.
As ofSuperman’s release, the DCU’s Batman hasn’t been cast. Andy Muschietti is working onThe Brave and the Bold’s script parallel to Matt Reeves’Elseworldswork onThe Batman - Part II. The latter will probably be released first, so the DCU’s Batman will probably make other cameos and be referenced through new easter eggs a few other times before he stars in his own solo movie.