We're also missing Lalafell, Viera, and Hrothgar children. But yeah, Banri Oda of the development team brought this up about how he'd like to see Roegadyn children someday but they decided to add Au ra children instead because of where Stormblood takes place. So it most likely depends on where the story's taking us to, if one of the locations is home to those races then we'll see their children. Male Roegadyn children look like small Hyur Highlanders, I can't prove it yet but that's what you'll see.