I think Gunn wants to keep his Suicide Squad continuity relatively intact. The Flash movie will probably reboot certain things and leave some stuff alone. I know Peacemaker Season 2 is purportedly in pre-production. At any rate, Gunn said Superman is the true launching point and Waller is supposed to pre-date that. So, I can also see Gunn using the Waller movie to close out the Syderverse. If there is a Peacemaker season 2, it will probably be written with the reboot in mind. On the other hand, Gunn's Suicide Squad is just disconnected enough from the first movie that he could zero in on that as the true beginning of the Gunnverse moving forward. Personally, I'd rather just cancel every movie not called Shazam 2, The Flash or Aquaman 2 and just do a 100% reboot starting with Superman in Summer 2025. Joker 2 can get an Elseworld title slapped on it. Pattison's Batman 2, as decent as that first movie was, should not move forward at this point.