While I agree with your logic, I am open to the point of view that some people would preferentially report someone’s behavior depending on the race of the person involved.
Perhaps a black employee is more likely to get a complaint about rudeness. If so, the race wasn’t made available but still changed the interaction.
I'm sure that's the case, and it will be up to the managers to be aware of unconcious bias on these types of reports and judge them respectively, but that's not going to raise a storm on twitter about a single person complaining about bad behaviour, or link that single complaint to an evidenced based dismissal later down the line.
Perhaps a black employee is more likely to get a complaint about rudeness. If so, the race wasn’t made available but still changed the interaction.