Speaking as someone who's had to live through DC comics murdering their entire setting multiple times over, the idea, while not horrible, is one that simply wouldn't work for me. Me, I'm more likely to go with my default explanation for Champions (It's simply another city on the same planet), or even take the solution that, while it wouldn't work for a lot of people, does work for me.
'And they all lived happily ever after'
'And they all lived happily ever after'