User blog comment:IHHeroes/Changes going forward after Crisis/@comment-25054842-20200116162051/@comment-28109177-20200116210154

Exactly, if these weren't the same people, Oliver would be here and Diggle wouldn't remembered Earth-1 Oliver dying trying to save Earth 38 because Diggle said he died TWICE, Again J'onn wasn't there for that, so he had to have restored all of their memories