Dwayne Johnson's Black Adam was going to be debut as the villain in an early version of do Gotham City Sirens instead.
During Suicide Squad 2's development, it was revealed that Gavin O'Connor ed the production to write and direct the sequel. The announcement came on the heels of The ant's release and made fans curious about what his vision would be. O'Connor worked on Suicide Squad 2 for close to a year before it was revealed he left the project, and Gunn took over. Since then, one of the biggest rumors about the film was that Black Adam was scheduled to be included as the villain, but it was never confirmed.
The Suicide Squad is in the midst of an early marketing push, and Empire has been the source of many photos and interviews as a result. What has surfaced online is only a snippet of the full coverage included in their magazines, but the cover story on Suicide Squad 2's development confirmed Black Adam was the villain of Suicide Squad 2 in O'Connor's script.
When rumors of Black Adam appearing in Suicide Squad 2 first circulated in late 2017, it was stated that the story saw Task Force X go on a mission to find a weapon of mass destruction, only they didn't know that weapon was Black Adam. Several months later, Guardians of the Galaxy Vol. 3 at the time. It still isn't clear why the studios and O'Connor decided to move in a new direction.
Without Black Adam, Gunn has taken The Suicide Squad in a completely different direction. There is evidence that the movie's villain will be Starro, an intergalactic starfish parasite that can control people. This hasn't been confirmed by Gunn, but one of the creatures can be seen momentarily in the behind-the-scenes video for the movie. It would come as quite a shock if Black Adam still appears in Suicide Squad 2, especially since Johnson moves full-steam ahead with the solo film instead.
Source: Empire
