It will almost certainly have the intended effect of dramatically decreasing the pay difference between negotiators and non-negotiators (which has a gender correlation, and possibly culture/ethnic/race correlations too).
It won’t necessarily entirely remove it. For example, if I get slotted as a junior engineer and therefore my salary is $X, is it possible that I could argue to be considered something else and get a higher salary? Maybe.
However, just because these loop holes exist doesn’t mean that the policy isn’t having the intended effect. It’s not like it’s an all-or-nothing deal.