I've never seen it applied to sexuality, but I have seen similar logic applied to religion; along the lines that a propensity to accept outside authority tends to increase the chance of children surviving to adulthood. However, once people are adults they "invent" religion to fill that need.

I suspect that there are multiple "personality traits" other than sexual preference that would affect the individuals tendency to conform or not to conform. Is their any evidence that non-heterosexuals are more "non-conformist" in other aspects of their lives?