Yea, this. Once there's no mechanical incentive towards or away a certain race, you'll see tropes and general aesthetics take over as the driving factor. WoW is a good example of this.
I don't think we're looking at no mechanical incentive here, though, just a lesser one. Which I guess is not entirely dissimilar to WoW.
The other issue that is dissimilar to WoW is that aesthetics are more much bigger factor because:
A) Each race has a specific, narrow, defined look that you cannot significantly deviate from. All Blood Elves are good-looking in a particular (I'd say "Californian") way. All Tauren males are hulking brutes. All Tauren females are curvy. And so on. This is not the case in pen and paper RPGs. If Goliaths existed in WoW, you could guarantee all males would be giant hulking monsters, like a linebacker on heavy steroids, and females would look like Victoria's Secret models who spent slightly more time in the gym (than the already large amount they do).
In D&D, though, if you want a scrawny Goliath, or a ripped-AF Elf, or a beardless Dwarf male, or bearded Dwarf female, or a gothy Elf, or whatever, all this is within your purview. Almost every DM will agree to anything like that.
B) You actually have your character on-screen, being seen by you and others, all the time. This is very different to D&D where many people don't even have portraits of their PCs, and certainly not ones that everyone is looking at all the time you're playing (even minis are different, because for 95% of people, they're only vaguely representational of the character, and not subject to the same scrutiny).
So overall, aesthetics will be far less of an issue.
But tropes will play in a bit, that is definitely true. But a big part of that will be people flipping and sending up tropes, too - people love to play against trope.