Yeah, if it were me, I'd let The Batman kick off a new universe and keep them mostly isolated (with the odd reference here or there) while WW and Aquaman finish out their respective trilogies. Maybe after The Batman's had a couple installments and we've got a new Superman movie or two, do a World's Finest film with the new Bats and Supes. Meanwhile Green Lantern and Flash have their new franchises launched. WW, Aquaman and Harley/Suicide Squad would likely be finished by then by a few years, so THEN do a new Justice League where you introduce a new WW and Aquaman. But that's me.