Montoya's probably not in a headspace/too career focused to be in a relationship right now. Meanwhile Sophie has, like, no career outside helping Ryan and the Bat-Team.
Now that I think about it, the Batwing suit is probably still in the cave.Poor Luke, he has been racking up losses left and right. Without access to the Batcave, Batwoman is going to need his help now more than ever.
Arrowverse world-building that they never intend to follow up on. Like GL .Didn't Crisis establish that was on another Earth? That was a weird throwaway line to mention Swamp Thing like that, but then, they did the same with Aquaman.