Did you not get the memo? All social constructs are biological. All behaviour has a biological underpinning, how could it be otherwise?
What I think this study shows (and its not the first) is that it debunks the notion that discrimination is the only reason for any differences in gender representation. If a particular field does not have a 50/50 gender split, then that must be wholly explainable by discrimination. This study shows that this is not the case. There is a component of the unequal split that is based on personal preference. And that personal preference has a biological component. This idea is taboo.
Which is also a notion that nobody has ever argued but suits polarized demagoguery.
For representation, if you increase the scope of the notion from "discrimination is the only reason" to "discrimination and unconscious social biases are the only reason", it certainly applies.