UPDATE: This is all but confirmed as The Rock is clearly teasing the Superman appearance in the interviews. He's making a big show of saying that he listened to the fans and they designed the story so that Black Adam is the most powerful and unstoppable force ON THIS PLANET. He says in multiple videos floating around today that the most powerful and unstoppable force IN THE UNIVERSE (Superman) has been on the sidelines for too long.
Possible spoilers for upcoming DC superhero movies. You've been warned -- turn back now if you don't want to know.
With that out of the way, word is circulating that Henry Cavill has signed back on to play Superman. The Marvelvision podcast dropped the info on two recent episodes. The show, hosted by brothers Devin and Derek Faraci, primarily covers the Marvel Cinematic Universe TV shows. They kick off the episodes with a rundown of breaking superhero movie and TV news. Devin says he has heard from a reliable industry source that Cavill returns to the DCEU as Superman in a Black Adam post-credits scene. Since these since these episodes went up, tons of fan sites are reporting leaks confirming this scenario, and the buzz on Twitter has "Cavill Superman", "Cavill Black Adam", etc. trending.
Supposedly Dwayne "The Rock" Johnson insisted that Cavill appear in Black Adam. This put Warner Bros. in a bind as Cavill was no longer under contract. In order to make The Rock happy and get him his Superman moment in Black Adam, WB was forced to negotiate with Cavill's reps and reach a new agreement. Previously, the character's big screen future was up in the air, with the studio considering various options for rebooting, recasting, etc. Apparently, this Black Adam situation led to a deal for multiple Cavill appearances as Superman, and the studio committing to develop a new Henry Cavill-led Superman movie. If true, this is huge news for a very vocal contingent of fans who desperately want the actor back in the role.
For context, Henry Cavill was cast as Superman for the 2013 Zack Snyder film Man of Steel. The response to the movie wasn't quite what the studio hoped it would be, so the decision was made to add Batman for the next movie. That gave us Batman v Superman: Dawn of Justice (2016), which led into the troubled production and release of Justice League (2017). And then the online fan movement that got the studio to let Zack Snyder come back and make Zack Snyder's Justice League for HBO Max. Cavill plays Superman in all of of these, but many people feel that none of them have really given him a chance to shine as the character. Others love the three Zack Snyder movies completely and just want Cavill to continue his run.
Warner Bros. Discovery has been very publicly searching for their own version of Marvel's Kevin Feige...someone to call the shots and make sure their handling of the DC Comics characters is on the right track. Maybe Dwayne "The Rock" Johnson is the man for the job.