That's a pretty unrealistic black and white picture you're painting. Cultures and groups within a company that are already diverse and are truly merit based aren't going to be bothered by these sorts of events. They're already got their house in order, so to speak.

The people you're describing of being so terrified by these events or adopting unofficial policies against women already had a misogynistic bent. They were already a problem. Them using an event like this to justify their anti-social behavior is typical, but it is not the cause. They weren't accepting bastions of equality until they were frightened into sexism. Putting them on notice isn't the end of the world for anyone.

Whether we appease bigots or confront them, some people are going to be assholes until they die. I'd rather confront them and leave no question about which way the world is going.