Yeah, that's exactly what's happening. People seem to be misconstruing my comment as endorsement of gender stereotypes? I don't know.
The assumption that the father is just giving mom a break is part of a systemic issue, that by and large women are still expected to bear the bulk of the burden of childcare. Older generations are much more likely to ask that assumptive question as they still see it as the norm. Hell, some families in my own personal circle fit that stereotype like a glove, to the detriment of the mother's mental health.