These comments are wild and the headline is not great. I know this is a contentious issue and that people like to armchair philosophize about stuff like this, but I think the study conclusions warrant a lot of critical attention before you say anything about "equality of opportunity vs. equality of outcome".
First off: this is one study. No matter where you fall on gender politics, I wouldn't hang anything too seriously on a single paper. Obviously gender discrimination has been a historical cause of the gender STEM gap; so are we saying that we've solved that particular problem? Is there still room to improve? How much room? To me it seems naive to assume the first one without lots of evidence, and this paper is not that.
Second: the regression shown in the article doesn't seem great. For one thing: there's a small cluster of countries with pretty high X values, and pretty low Y values which suggests that they have relatively high leverage over the results and should probably be excluded. If you cover up UAE, Tunisia, Algeria, and Turkey does the regression line make any sense at all? To me it seems way too steep, ie. leverage. (Maybe the authors talk about this in the paper, I can't get behind the paywall). Also my priors would be that there are a number of country- and regional-level effects at work for an issue like this. It would be way more informative if the authors were to perform subgroup regressions by region of the world, cultural factors, ecnomic factors, etc. It's very possible, for example, that these two variables have an opposite correlation within region, education system, etc, but appear to have a negative correlation on aggregate. Simpson's Paradox is real and can cut many ways.
Third: choice of metric. Per the article
"""In this study, the percentage of girls who did excel in science or math was still larger than the number of women who were graduating with STEM degrees. That means there’s something in even the most liberal societies that’s nudging women away from math and science, even when those are their best subjects"""
This could be caused by a lot of things, but this suggests to me that the "Global Gender Gap" metric may not be giving us the whole picture. I think it's real hasty to draw basically any conclusions about eg. the US STEM culture based on this study. When the results suggest a paradox like this, I think it calls for looking at a variety of metrics to see if the same results are borne out repeatedly.
tl;dr there's a lot of research on the gender STEM gap, and a lot of people shooting from the hip in these comments.