Judging people's fitness for a job based on the dialect of English that they speak is by definition a form of bias. That it's bias that is also reflected in the workplace pre-LLMs doesn't make it not bias.
Also, by definition where? You’re just making this up, there isn’t an authoritative dictionary or even regulation that states judging fitness for a job based on the dialect of English a person speaks is “bias.” If there was, surely you would have provided a link instead of just asserting your own correctness.
Perhaps the model is only accurately learning that more educated people use a particular dialect of English taught by universities.
There's really no way to tell, because the researchers didn't include other dialects of English that aren't favored by universities, like southern, or Yorkshire.
It does make it not bias when an LLM is accurately representing reality.
Obviously as a normal person I'll say that in normal life and in most work situations.
So if a dumb cunt can't show they know what to do in a interview I'll judge them on that.