Could be lots of reasons.
Typical symptoms of autism in men and women differ and often women can more effectively mimic and so can deal with getting out of the house better and the social side of getting work and living independently.
More women then men go to uni which is good practice for living away and making friends who you may live with.
It's possibly that sone of the women are moving in with weather/older men rather then working and earning enough to live on their own personally.
Women tend to be better trained in life stuff so leaving home is less intimidating.
Women tend to perform better academically and possibly are more attractive for graduate jobs (before the inevitable maternity bias kicks in).
The council house answer above is interesting and may be a factor. Women with children are generally prioritised above single men. Single women with kids are more common then single men with kids.
Do we know if separated men are more or less likely to return to parents house then women? If there are kids involved and mothers are more likely to be primary parent, dad's are more likely to be the one moving out of the marital home and if the mother moves out with kids they are more likely to move to another property rather then to parents because of space issues.