Well if we compare it to IRL history it would be the oldest civilizations I guess (Rome in form of Italy, France, Spain; Greece, China, Japan etc.) , somewhere even the ones preceeding the 'oldest' we know prevailed (e. g. Etruria - Tuscany). They would have to either protect themselves from other influences or just straight up BE the influences.

In this vein, I'd say the Kaldorei (and other elves), Trolls and maybe some Old gods and Titans would influence others and keep their names mostly, f. e. Azshara (the region) kept its name even after the fall of the Highborne capital, Sundering and so on while Horde controls it mostly now or I think even Un'goro is from Qiraji, something like God-land. Even Kalimdor is named by the titans. I guess the Draenei filled that place in Draenor since Arakkoa were reclusive and ogres more war-like than the administrator type.