When James Gunn and Peter Safran took over as the co-bosses of DC Studios at Warner Bros., it didn't take long until the DC Extended Universe (which was started by Zack Snyder with Man of Steel) was executed and put out of its misery. This paved the way for the DC Universe, which will properly begin in July with Superman, even if Creature Commandos did technically start things off and Peacemaker will seemingly serve as a bridge between the two universes.
Regardless, many saw this change as the reason why Henry Cavill, for one, was ousted from the role of Superman, as Gunn and co. needed a new tentpole figure to base their new universe around. However, this might not actually be all too accurate.
Speaking with Entertainment Weekly, Gunn states that Warner Bros. was looking to get rid of Cavill even before he and Safran joined, going as far as noting that plans were in place to find a new Clark Kent before Gunn decided to make The Suicide Squad (which premiered in 2021).
Gunn claims that Warner Bros. wanted him to direct a Superman film back then and that "it was even more messy than it is now," while also noting the reason why he didn't take the job at the time was because he "didn't have that special idea of what that [film] would be."
So, while the future will see David Corenswet donning Supe's cape, we shouldn't necessarily blame Gunn and Safran for being the reason that Cavill isn't the star of the show anymore.