The claim is they disproportionately benefit.

Granted, your use of the word "disproportionate" at least rules out the trivial interpretation. Not everyone does this - it's common hear a claim like "most of the benefits have gone to white women" which is compatible with a trivial interpretation. My thoughts above are about this phenomenon in general, rather than your personal take on it.

Second, they take the gaps in positions held before AA and compare them to the gaps now. White women have made larger gains than other groups.

So the metric here is 'number of people employed' and you're telling me that the ratio by which 'number of white women employed' has grown is greater than <insert other group here>?

I'd want to see the numbers (is it really a great ratio rather than merely a greater absolute number?), and I'd want to know which other groups (what about groups of minority women in particular?), and I'd want to know what happened in the term periods before and after - has the study interval been cherry picked; is this just a continuation of a pre-existing trend that came about for other reasons than AA etc.

There's a looming danger of the post hoc fallacy here. You can see that, can't you? I mean, one can't pretend this is a controlled experiment - you can't simply look at variables A and B that have both moved and infer that it was the change in A that caused the change in B (rather than A', A'', A''' etc which have also changed).

I don't understand what you're saying here. Are you saying that the plain truth is that AA wasn't intended to benefit white women?

What I said is exactly what I meant.