"forgo an in-person interview altogether. Which doesn't seem like a good idea"

I would disagree strongly in that YC has a measurable financial risk of excluding potentially profitable founders solely for meaningless cultural woo woo reasons. For example if some Finnish dudes conduct perfectly normal business transactions nude in the sauna, a prudish American who refuses to participate has an obvious measurable economic loss solely because of irrational cultural woo woo. Now extend that far out example into female communication style.

Now what would work, or at least would be interesting, is having a female partner interview female founders separately from the male partners then study the female partner's impression vs male partner impression. I don't suspect there would be a huge difference; but at least this would be a somewhat more effective way to test the proposed effect. For my ridiculous made up example, you'd need a Finnish partner; probably easier to run this test on the somewhat easier to acquire and categorize male vs female test subjects.