I have to disagree for one reason and one reason only: "Rule #1: No Time Travel
In Earth-27, time only ticks forward. Time might be slowed, sped up, stopped, or bypassed but it cannot be reversed. As a result, some characters’ origins may have been reworked to allow them to feature in Earth-27 (such as Booster Gold or the Reverse-Flash). The decision to do this was to establish a world with real consequences and to avoid messy time travel storylines."