Agreeing with almost your entire post; however, the word "
copacetic" in 1930s slang, introduced into the mainstream by Cab Calloway.
And even my slang hating and abjuring father used that word, long before The Dobie Gillis show appeared on T. V.!
That show and an early movie, taken from the original book ( THE LOVES OF DOBIE GILLIS ), which takes place on a college campus, NEVER used that word.
Having been very young at the time, elementary school, I just recall that the kids who watched that show picked it up and it only became more commonly used among elementary school kids as the the show became popular. Before it became popular, I only ever heard it from one friendly bus driver who was probably, when I think about it, a Cab Calloway fan.
Popular among a younger audience might be the best description of what I'm thinking in the way of media influence growing.
Regards