Even without such a study it should be intuitive that steering neurotypical (in the broad sense) boys toward typically female preferences and activities, and vice versa, will end up being cruel along some margin.
(Just as it's certainly cruel for an atypical girl to be forced into typically female behaviors and preferences, which is what you're describing.)
The question is, where's the margin?
The synopses of the book that are on the internet don't inform of the degree to which it's an actual study by a sociologist; it's not a pop-parenting book.
Given our ignorance, though, and the likelihood that along some margin or another this becomes a zero-sum game between the atypical and the typical, I'd rather see a little less swashbuckling from the more aggressive advocates of undoing gender expectations. Much of this looks like surgery by sledgehammer to me.
http://phonaesthetica.com/2014/02/21/heres-how-it-ends/
http://sodisarmingdarling.tumblr.com/post/34106027759/what-i...
http://www.metafilter.com/121190/teenage-girls-they-havent-b...
http://www.bbc.com/news/education-25138455
http://www.theguardian.com/lifeandstyle/womens-blog/2014/jan...
http://www.salon.com/2014/04/14/report_many_girls_view_sexua...
But a world in which your vision ("Gender needs to go" == "your conception of gender norms needs to go") is realized is one where many more suffer similarly oppressive expectations. And anywhere in between we're making tradeoffs that are costly to someone on some margin.
Somewhat relatedly: "Theor[ies] of oppression" would be all the more compelling if the humanists and sociologists who peddle them for a living bothered (or had the training) to think in terms of general equilibria.
Men benefit directly from how women suffer under gender. Did you read any of the articles? The only reason any of that occurs is for the benefit of the men in the society. The demand is for girls/women to "make themselves sexy," sexy being defined as appealing to straight men's sexuality. The idea of "oppression" has always implied an oppressor class -- attempting to revise the idea as to not include you and I in the class is only expected, though. "Sociologists"? Try Marx.
I don't "favor" any gender expectations. I don't know what you're referring to. The worldwide conception of gender, facets of which is illustrated by the articles, needs to go -- you can read what this would be like in the short essay "Imagining a World without Gender" by Judith Lorber [1].
[1] http://paste.pound-python.org/show/QGJwDfVVulEjLTdEmdmU/
So could one say that we do need to focus on girls, to the extent that we recognize the socialization they receive in a society where gender roles are a thing? I agree with the article in general -- though I don't see anything wrong with programs for girls who have already found themselves teenaged and without the resources to get the necessary programming/STEM experience, and/or being uncomfortable around teenage boys in a field that the boys have been taught is their turf.
The media should promote some more female STEM role models. It would make up for the years of degredation and exclusion of women in STEM on TV, in the movies, etc -- especially in kid's media, where girls and women are usually token side-characters when they aren't princesses (see reelgirl.com for thorough documentation). It'll never happen, of course, despite that it would hurt no one, because the necessary critical thinking, along with the knowledge of women's history, to keep ourselves from shouting "gender bias!!!" at anything helping women succeed, is absent.