No, women are allowed to leave Ukraine because, for the most part, they are responsible for raising the next generation of Ukrainians. The number one long-term job of any society is ultimately to raise the next generation. If you don't do that, the society doesn't exist in one or two generations' time.

What you consider misandry is in fact a feminist issue. Women often don't choose a life of childcare; it's something that can be forced upon them, because if they don't do it, no-one else will. Men get to choose whether to get involved. If the share of childcare was more equal, then there wouldn't be a reason to restrict leaving the country on a gendered basis.