The rapid homosexualization of the US population over the past 3 decades shows how sex ratios become imbalanced and unequal. It's now not possible for a large percentage of males under age 30 to even date a woman due to higher rates of non-heterosexuality in females. You can read the study and see for yourself.
Now, it's possible the homosexually displaced heterosexual males will turn to drugs, booze, video games, or other activities and nothing will happen.
Or it's possible some of these males will realize that they're victims of a world that's thrown them overboard and violence will ensue. It may create a small civil war or regular acts of terrorism. Only time will tell.
When a large enough portion of males realize women may legally wed women, yet they as men are mathematically eliminated from doing so, I predict violence. In fact, we may have already seen some in the past college shootings.