Even if it happens to be “optimal” in this case at assigning employees to positions based purely on the information available and their likelihood to succeed, biases can present other issues.
It's like having people or neural networks choose door 1 from door 2 without clear advantage to either of them and without making it clear that one door somehow represents "donating blood" while the other represents "kicking puppies".
Philosophy sometimes says that knowledge is a "justified true belief"*; in this experiment, agents and humans have incorrectly justified a false belief that some applicants are better for certain roles.
* other times, it says this isn't good enough