This entire article’s premise fades to simplicity and obviousness if you reverse the direction of causality. Instead of suggesting that a healthier society’s men prefer more feminine women, consider that more feminine women are more likely to appear in a healthier society. In a less healthy society, the women may subsequently not look as feminine.
But that does not mean a man in sick society will prefer more masculine.
Yet, they say it does here. They’re still looking for more masculine, not the few feminine that appear.