There would still be roughly 4 million men left globally. Humans have survived worse die offs. But I would say a lot of woman would probably never have kids. Or boy's who survived birth if what the story implies is true about the virus killing new born boys. Pretty much only a few countries...
War, violence, and discrimination are the side effect of being a spices of territorial predators that form groups. Having big brains just takes it to the next level.