My pleasure! I love tough questions (occupational hazard).
To change the societal norms, the first thing we need to do is remember that we aren’t going to change an ancient system of norms overnight. Besides our outdated notions on sex and gender, we have outdated notions about the nature of talent and how to do hiring in the 21st Century (both are long stories and long consulting cases =P). In short, we tend to have fixed notions of talent, fixed ideas about the origins and development of talent, and want to get very specific types of people into tight job pigeonholes (which is often not a strategic hiring practice).
As with every talent pipeline problem, you have to fix the entire stretch at once or nothing will change. For instance, we can make interest groups for women, but they will amount to nothing if the workplace isn’t friendly to family leave and still gives women a hostile work environment. We can make programs for high school girls, but if they face horrific hazing in the college’s computer science major, the programs won’t work. The long answer involves in-depth analysis of each company and each field and programs that address all of the issues at every level, from tot toys to top management.
A gender gap is never a problem in and of itself, but it is a warning light that something’s very likely not to be working properly. If there is a gender gap, but all of the capable women who want to work in tech are able to do so as fully as their capacities allow without having negative experiences that relate to their sex and gender (as I defined them in the article above), then (and only then!) I would have little (but not zero!) concern about a gender gap.