Like Kagehiro said, they probably wanted to avoid another Shadowlands issue, where things feel so alien that it doesn’t feel like Azeroth, or even Warcraft anymore. Pandaria had a similar issue and fanbase reaction; pandas, monkey men and fishmen didn’t feel familiar enough, therefore “Warcraft” enough (even if Chen existed before).
And if you look at the other expansions where we went to strange new lands, they all had familiar faces; Legion had all the night elves and some tauren, BfA was all faces we’d already seen, Dragonlands was dragons we knew and a bunch of bland evil henches for the baddies made up of player races, and now? Rock dorfs, humans, driders and trolls. And casual fans feel it’s all Warcraft-y (except maybe Dragonflight, because dragon pals I guess).
And really, there aren’t many other options beyond humans and elves. I guess it could be another flavor of dwarf, but we already have Vanilla, Wild, Dark and Earth Dwarf flavors. It’s just as bad as human (Basic, furry, chunky and dead) and less bad than elf (Real Night, Superior Blood, Emo Void, Fake High, Temu Night). But beyond elves, humans and dwarves, who else has a habit of expansion?
Trolls have been in decline since before the night elves blew up their continent, so a whole other continent with more trolls feels wrong. Tauren aren’t expansionistic and neither are gnomes or vulpira. Pandas are from Pandaland, and have been also since the night elves blew up a continent. Draenie and orcs are aliens.
So our friendly familiar face that isn’t a human, elf or dwarf would be… Goblins? And they didn’t exploit every natural resource already… How? Or cause a total ecological collapse?
So more dwarves, more elves or more humans are really the only good options. At least with the Arathi, they get a baked in way to throw another version of elf in too by saying some of the elves that came with them got bored and made a kingdom or something.
It’s crappy, but WoW’s playerbase isn’t known for their embrace of different and unfamiliar things. It’s the boring option that at least won’t push people away.
And hey, humans get a pointy ear customization option now, so that’s a thing!!
EDIT: Sorry for the rant. And this isn’t really directed at you, just me venting my thoughts.