I'm not sure why this surprise or even disappoints players, this is what allied race are.. they are sub-races we've wanted.. they are based on existing races with some distinct modifications:
Nightborne = night elves that are skinnier, upturned ears, darker tones and arcane runes. Unique face
Void elves = blood elves that are more ripped, purple skin/hair/eye shading, and in-combat void swirls animation, animated hair. Unique face
Highmountain = Tauren with tattoos and huge moose antlers you can't mistake for a tauren even though same skeleton.
Lightforge Draenei = Draenei with grey/white skin, visible Naaru symbol and Light runes (they could probably use an extra visual distinction)
Zandalari Trolls = Darkspear Trolls upright, different ears and modified face
Dark Irons = Dwarves with different colour scheme and different gait, red eye glow
They are all based on existing races, some have more modifications than others, some could do with maybe an extra distinguishing feature (I'm looking at you Lightforged draenei) but this is what they are, when we saw Dark Irons, Nightborne, Highmountain, Taunka, MAg'har orcs, Lightforged, Leper gnomes - we wanted them as races in their own rights, with those looks and skin textures, preferably in higher detail.