Probably unless they escaped to Earth Prime when the red skies showed up.
Flash had some stuff in tonight's episode but I think the bulk of it will be on Arrow. So far there's been nothing on Batwoman and Supergirl. Batwoman is probably focused on getting to the present (at the moment the show is pre-Elseworlds) and I bet Supergirl will do their usual thing of having a crossover connection the episode before.
I don't remember if we got any info on who gets Mia or why she's brought into the present for Crisis but, until I know otherwise, I'm hoping it's because Sara learns Oliver is destined to die and sends for Mia so he can get to know her. At the very least I want Oliver to tell Sara his destiny before the fighting starts. Felicity and Diggle are the first to know, and they should be, but Oliver loves and trusts Sara almost as much (I'd say just below them if I were making a list), and knows she's the same with him, and absolutely needs to tell her. Plus it will give me Oliver/Sara goodies and we're running out of time for those.