I'm honestly surprised we haven't gotten an update of the Warcraft RPG. I thought it sold well enough? Plus like, Lands of Mystery was basically "Hey, want to see our ideas for Wrath? Here you go". Love that book. Also love the fact it has playable stats for Murlocs, Nerubians, Blue Dragons and fricking Magnataur
But yeah, I'd almost grab from winged tiefling outside of dragonborn because the breath weapon seems associated with Evokers specifically. When we get them split out to other classes, I suspect the other Dracthyr won't have the breath weapon. Their specific racial is a tail smack to be precise, so some sort of limited flight and a tail attack would work for the base Dracthyr, then just some sort of thematic class for evoker specifically