I would have rather they went all out and did this as animated instead of live action given the sheer number of characters involved. As much as I love COIE, I don't think its story stands up to the test of time considering how DC has not only reversed course on having everyone on one Earth but has exponentially expanded the Multiverse concept over the last few decades. They started by adding in Hypertime, then the whole 52 concept, a couple of sub-par Crisis events in between, then the God Awful Flashpoint which resulted in them folding in Wildstorm and the reclaimed characters from Vertigo, and finally here recently with the Dark Multiverse stuff that spawned nonsense like The Batman Who Laughs (sorry...I don't care for the Joker and having a Bat-Joker excites me even less).
Maybe it is a good thing it's live action. It'll be limited in scope to the shows in a sense and it won't have Didio involved to inevitably screw things up.