By Arrowverse-Crisis rules, if it were a rewritten history of the same universe, its individuals would still look the same, just have different memories. It would have to be a separate Earth that just happened to have certain individuals and events in common, like how Superman & Lois's Earth and Earth-Prime had identical Clark, Lois, and Diggle, but very different versions of Sam Lane, Maxwell Lord, Lex Luthor, etc. Or, as I mentioned, like how Young Justice's Earth-16 includes some of the same individuals and events as Green Lantern: The Animated Series, but is otherwise a distinct reality.