Last year, DC Studios co-CEO James Gunn clarified some confusing comments he made about the first season of Peacemaker, which he said he didn't view as being canon with the new DCU despite the upcoming second season being firmly established as part of the burgeoning shared movie and TV universe.
While speaking to IGN, Gunn revealed that "almost all" of Peacemaker season 1 is canon, with one notable exception.
"In Creature Commandos, you'll hear them talk about things that happened in [The] Suicide Squad or Peacemaker,” Gunn explained. “Well then, those things automatically become canon.”
“The truth is almost all of Peacemaker is canon with the exception of Justice League," added Gunn. "Which we will kind of deal with in the next season of Peacemaker."
As expected, the sequence featuring members of the Justice League showing up way too late to save the day in the season finale is the one aspect that will not carry over to the second season or the wider DCU - but it doesn't sound like this is going to be retconned in the way we expected.
The Quantum Unfolding Storage Area is an extradimensional room that was created by Christopher Smith's (John Cena) father Auggie, aka White Dragon (Robert Patrick). This "pocket dimension" tech will likely explain why Peacemaker appears to encounter an alternate universe version of himself in the trailer, but it won't be used to retcon the Justice League's appearance in the season 1 finale.
"People are realizing that Peacemaker Season Two is about two dimensions, and that’s really the core of the show," Gunn explains to Rolling Stone. "But it’s not as if one of these is old DCEU and one’s DCU. That’s dealt with in a different way, very upfront in a season where most everything in Season One is canon and some things are not. And in fact, I did a podcast with [actors] Steve Agee and Jen Holland. And we did every episode of Peacemaker, and in those episodes, I talk about what’s canon and what’s not. I basically chip off little things from Peacemaker Season One that aren’t canon, like Aquaman. But most of the stuff is canon."
How the old version of the League is wiped from DCU canon remains to be seen, but it's entirely possible that Smith and his allies encountering those characters simply won't be brought up!
Gunn recently revealed that we pick up "roughly" two years after the events of season 1, with Peacemaker attempting to be taken seriously by the superhero community.
"We come into season 2 with Peacemaker knowing that he saved the world from the Butterflies," Gunn says. "He thinks he's a big star now, and he should be a real superhero. And we see at the very beginning of episode 1 that he's meeting with the group of superheroes from Superman, and he's basically interviewing for membership in the group. But they just mock him the entire time, so he's not taken seriously."
"He's still considered a punchline among all of the other metahumans, so he's starting the season in a bad place," he adds. "As are all of our heroes, all of the 11th Street kids — well, everybody but Vigilante [Freddie Stroma], who just always seems to be okay with everything."
"The new season follows Christopher 'Chris' Smith, aka Peacemaker, the vigilante Super Hero as he struggles to reconcile his past with his newfound sense of purpose while continuing to kick righteous evil-doer butt in his misguided quest for peace at any cost."