Junkers are not Gnomeregan gnomes and would not be customizations for the latter, that ship sailed when Blizzard decided that Lightforged, Highmountain, Dark Irons, and Mag’har were worthy of being their own races instead of just barbershop options. They’re a separate model from Gnomeregan gnomes with unique animations that highlight their half-machine nature, it would be easier to just release them as their own race instead of retrofitting their cybernetics and hairstyles onto the classic gnomes, assuming that’s even possible.