So…if we start from BC onward…
BC: Arakkoa (both low and high borne options just as cosmetics)
WotLK: Taunka, Tuskar, High Elves (Silver Covenant was a thing) heck, could get the Nerubians too!
Cata: Quillboar, Gnolls, Ogres, Firbolg
MoP: Hozen, Jinyu, Klaxxi, Mogu
WoD: See BC, nothing really new here
Legion: All this was was demons really and nothing really living on Azeroth
B4A: Still need the Sethrak, Tortolans, and the sea goblin dudes (god I hate Nazjatar without flight, why must the maps be designed to be so unpleasant without it?)
SL: Honestly don’t think any of the SL races should be made allied races due to the anima dependancy and how that couldn’t really be fulfilled in Azeroth
Also: noticed how I didn’t list a faction? That’s cause I think the hard lock for race/faction needs to go the way of the Dodo as the factions have worked a ton with each other, and we are supposed to be ragamuffin adventurers, not leaders of a given faction so we should be able to pick and choose who we work for!