As stated in the title Earthern heritage transmogs are able to be used by all dwarven races in the game.
This should be reflected by all races, such as Tauren and Highmountain Tauren / Orcs and Draenor Orcs / Draenei and Lightforged and so on, they should also be able to share heritage armor as they share their culture and knowledge with each other.
You can’t have it work for 1 set of races and not the others. Either have it for all, or not at all.
Lastly can Mulgore Tauren please get Baine’s Chieftan Headdress? The one we have now is called [Ancestral Chieftan Headdress] - yet it looks nothing like a Chieftan Headdress which is what Baine is wearing… Bit of let down…