A majority of Dwayne Johnson’s recent blockbusters earned PG-13 ratings, including (but not limited to) Hobbs & Shaw, Skyscraper, Rampage, and the Jumanji movies.
Johnson’s last R-rated movie was 2017’s disastrous Baywatch, which was a critical and commercial misfire that tanked at the box office.
Ultimately, the safest bet is that Black Adam will become a PG-13 feature.
It is possible that Black Adam might also try to push itself to be an R-rated spectacle, especially given how gruesome the character’s new origin story was in the new 52.