Technology

Found myself a copy of the paper for a read-through and it's immediately obvious to me why they couldn't get above 90% accuracy.

The word "Gender" occurs exactly zero times in the text and the datasets they worked with were divided into a strict sex binary. As a result, the accuracy of their models' predictions could not significantly improve upon prior work in the field.

The only new info here is that their XAN is able to point out the specific brain features that influenced its predictions. Potentially useful with regards to the development of treatments for gendered brain issues in neurotypical people, but anyone who falls outside of the 90th percentile of sexually dimorphic normativity won't see any benefit here.

Brains change over time. The outcome and interpretations of this study sound like they have more chance of causing harm than good.

I would be curious what this would predict for trans (including those both on and off hormone therapy), intersex, or homosexual individuals. My guess is that at a minimum in those cases it's accuracy of predicting either their gender or sex would be very poor, although it would be absolutely fascinating if it accurately predicted their gender rather than their sex. The opposite result (predicting sex but not gender) would also be interesting but less so.

inherent sex-based brain variations

These findings could lead to personalized medicine approaches by considering sex differences in developing treatments for brain disorders.

Yep. There are observable differences and it is good we are increasingly able to take them into account.