see for example Unlocking the Clubhouse: Women in Computing (MIT Press) http://www.amazon.com/Unlocking-Clubhouse-Women-Computing-Pr...
You added the idea of conscious planning. Replace "plan on supporting them" with "higher probability of getting support".
> tons of evidence around sexist cultures in engineering and CS
This has no bearing on the above claim though, does it? That men have a higher risk of being able to find a partner capable and willing on supporting them financially.