It was 105 today. That trend might come back out of necessity.

i believe that the cultural shift away from ordinary men letting it hang out publicly happened at a time when air conditioning became less of a luxury item that only the wealthy enough could afford; when awareness that straight men can also be sexualized became common; as well as when this country started to become more conservative politically (ie going from cultural, feminist & sexual liberation movements from late the 60's going into the 70's to the reagan & aids-scare of the 80's leading into big anti-lgbtq & "family values" policies from the federal government in the mid 90's).

considering that both presidential candidates are right of center in our current overton window (at least much more so compared to the 70's); air conditioning increasingly being required by law in many places; straight men generally still being terrified of being perceived as gay; and the gen-z tendency towards merely tolerating sex positivity instead of embracing it like in the 70's it leads me to believe that it won't come back for a long time, if ever.