The Suicide Squad featured the shocking death of Rick Flag, a moment which proved pivotal in Peacemaker when Christopher Smith was forced to come to terms with the murder he'd committed at the behest of Amanda Waller.

While the Dceu is being rebooted as the Dcu by James Gunn, many ideas from his past projects will carry over. That's created a lot of confusion among fans, though it can likely be explained by at least some of what happened before having still taken place in this new reality. 

That's likely why Frank Grillo's Rick Flag Sr. will be on a mission of revenge, targeting Peacemaker after what he did to his son. 

Gunn was asked on Threads about the fact Grillo's beard colour is different across Creature Commandos and his live-action appearances. When it was put to him that "some are linking [Rick Flag Sr.'s] hair with the timeline," the filmmaker responded,...