Classic Hits/Oldies-formatted stations are on a real hot streak, having shown growth for eight consecutive years according to Arbitron; removing sixties music and freshening the format with more eighties product, of which there is an abundance of, has done wonders in boosting the ratings for many such stations, including format legends such as KRTH/LA, celebrating its 40th anniversary this year.
Like I said, time marches on. I think 60s pop on terrestrial radio is dead, like 50s golden oldies and 30/40s nostalgia before it. And early 70s AM gold isn't doing well, either.
I think we're going to have to get our 70s stuff in dribs and drabs, like disco on old-skool R&B stations and New Wave on AAA stations.