This study is about same-sex friendship preferences, so the frequency of interaction with members of the opposite sex in these cultures is not the most relevant

This study is about same-sex friendship preferences, so the frequency of interaction with members of the opposite sex in these cultures is not the most relevant. That being said, I agree with the person you are replying to. Differences in friendship preferences by men and women could be highly variable in different cultures, so one shouldn't read too much into a study that looks exclusively at US participants.