That's assuming they'll all merge into one Earth. Which I highly doubt. Too messy.I understand. What of The Flash (1990) then? I'd assume that would stay, of cause, but it's existance creates an inconsistency with the other shows. Pahaps that should be inserted into it's own timeline?
Maybe just a note at the top of the CW Multiverse should do.
Black Lightning is a CW DC show, so it will probably be in the post-crisis Earth, especially since it's not just going to be cancelled.