Obviously if someone does work overtime/full time, they should still do whatever they can to ease their partner's load and be an involved parent. But if a couple has one person (of either sex) working part time, and one working full-time/more often overtime, it makes sense the first person would do more housework etc, at least to some degree.
But I'm wondering how much of a factor it is in the issues of the second shift/mental load etc Studies show men tending to overestimate how much housework they do- but do couples who both work full-time or both work part-time have more equality in who does housework & childcare?
I think that is the most informative comparison, since if a couple has one person working full-time/often overtime it doesn't mean they should leave everything else to their partner who works part-time, but it does play into the issue.