User blog comment:MakeShift/The Crisis and its impact on the Arrowverse Wiki/@comment-24476516-20200123052046/@comment-807326-20200123052758

While they seem like the obvious choices, technically speaking the Crisis was still occurring well after the multiverse was reborn, so using them would be inaccurate. We did consider just "original" and "new", but that felt a bit non-specific, so we went with what we've got now.