This has been discussed before but I saw some stats that illustrate how strange BYU is for freshman from the perspective of male/female mix. In 2013 and 2014, entering freshman were 30-31% male and 69-70% female. The missionary age change was made in Oct of 2012 and so the 2012 numbers look more "normal" at 45% male 55% female.

I don't know how BYU freshman females see this, but I would guess that they don't love this scenario. Sure, the numbers balance out over time because many of those 18-year old missionaries eventually enter BYU. But there's got yo be something unsettling about the freshman experience when 70% of freshman are female. I guess that's favorable for the guys but not sure the girls feel the same.

As long as more males than females serve missions, BYU will always have an imbalance. And college students across the US are 50%+ female at virtually every university. But BYU's 30-70 situation is very unique and I think it definitely represents an unintended negative side effect of the missionary age change.