That definitely seems possible. I have also read some interesting stuff around how women tend to end up a few years behind their male counterparts due to child care, maternity leave, and them choosing not to take less demanding positions to spend more time with kids. There is a lot in there to unpack and you could still argue it is a societal discrimination thing (women are expected to do more child care duties), but that is not an argument supporting pay discrimination at a corporate level, but more of a societal shift that has to happen between child rearing partners. I don't know if this matches up with data and studies, but just logically, it is inevitable for a woman to have to take at least a little more time out than a man due to the biology of child birth and child rearing.

I think all of this points to women not attaining the same rank/position as the key factor in gender differences, not a discriminatory pay gap.