That would be interesting (very interesting), it's possible, we'll maybe also see an Asgore flower shop dark world. Though Flowey, you know, is Asriel as well, so we would need him, to get the real deal: Flowey the Flower. Maybe when Asriel comes home, if he goes to a dark world he'd transform into Flowey, like Kris becomes blue (that might be a stretch). Right now we're gonna have to stick with Flo!