According to the comic books and Dwayne "The Rock" Johnson, Black Adam is a powerful being with no equals on Earth. But, DC Comics and DC Extended Universe are also home to extraterrestrial beings that are equally as powerful. Case in point, Clark Kent, otherwise known as Superman.
This is something that The Rock alludes to in a recent video. After hyping up Black Adam's strength, The Rock specifically repeats "on this planet" before winking at the camera.
If that doesn't confirm Henry Cavill's return as Superman, we don't know what will.
The Rock isn't afraid to stir the pot, so to speak. Last year, The Rock drew the ire of fans for saying that Superman can't beat Black Adam. Since then, The Rock has spent the past few months generating hype for Black Adam while also teasing Cavill's involvement in the film. It's possible that Warner Bros. Discovery initially didn't plan on bringing Cavill back to be Superman again but had to make changes to accommodate Johnson.