Title of that section is:

"Context is critical when evaluating if a group is 'underrepresented'"

Because it's not only illegal to ask about those things directly, but also question designed to uncover them. Like you can't ask what hair products they use to see if they have nappy hair.

HR is telling them do it sneakily, trying to get the candidate to volunteer something and to keep the discrimination decision criteria under the table. Not a lawyer, but this has got to increase their liability a thousand fold.