Dwayne Johnson's The Suicide Squad. However, going back to this more mature rating would have been a big mistake, as it would have created a major problem for Black Adam's future.
Since Black Adam is the introduction of Dwayne Johnson's DC character, audiences would expect that he will continue to act the same in future appearances. Black Adam being R-rated would not mean this is possible, especially in regard to the levels of violence he will use. The DCEU movie is going to push the boundaries of what Black Adam is capable of in a PG-13 setting. While that might have forced the film to cut some more violent moments, it is better to do that than risk making it seem like Black Adam's powers and ruthlessness were scaled back going forward. The reason is that Black Adam's future appearances will not be in R-rated DCEU movies.
Black Adam’s R-Rating Would Hurt His Eventual Superman Fight
The potential R-rated Black Adam movie would also hurt the future fight between The Rock's Black Adam and Henry Cavill's Superman. There is almost no scenario imaginable where Superman stars in an R-rated movie, so the Black Adam fight would have to come in a PG-13 movie. Since his violence is what almost gave Black Adam an R-rating, there is a suggestion his fighting would have to change then when going against Superman. Toning down Black Adam's violence and strength when he goes up against his most powerful opponent would not make any sense, though. Superman deserves Black Adam's full strength as shown in the movies.
Now instead of having to figure out creative ways to explain Black Adam's scaled-down violence, the Superman fight can proceed as normal. The Rock continues to tease his desire to fight Henry Cavill, but no official announcement has been made. Audiences are most likely to see Black Adam and Superman fight in Black Adam 2 or the latest attempt to make Man of Steel 2. Either DCEU movie should retain a PG-13 rating and allow the heavyweight DC characters to square off in an epic blockbuster setting without worry about how Black Adam's violence stacks up to a prior R-rated appearance.
An R-Rated Black Adam Would Not Work With The DCEU’s Plans
The DCEU's future is also easier to build without an Birds of Prey underwhelming financially. The chance that Black Adam will help restart the franchise is greater with a PG-13 rating and The Rock's ability to market giant blockbusters for everyone to see. That's not to say an R-rated Black Adam movie would not be successful but rather that it is a better decision to avoid that rating to help position Black Adam as a key DCEU character.