No, I said oldies didn't evolve into classic hits.
Some stations remained oldies and continued to play the 60s and 70s. Others chose to be classic hits and played entirely different decades.
The change was evolutionary. Stations that had been playing 60's and 70's in markets that could afford research slowly dropped the older songs and, just as slowly, added more 80's until the format was solidly 80's based.
Stations did not want to age with their audience if that meant that the audience was becoming almost entirely over 55.
A few that had stuck with a lot of 60's and 70's made, at some point, a dramatic change and got rid of the older songs.
The main reason for the changes all along was that ad agencies were not buying listening over age 55. The few stations that kept the "oldies" music of the 60's found that they could not sell to agencies and were confined to local direct sales. And the term "oldies" at agencies became a translation of "don't buy this station".
Some stations did indeed gradually move closer to the current time in trimming their music libraries than others. (Some did it a little
too gradually, as witnessed by the huge negativity in comments during Jay Coffey's tenure as PD at KRTH.) Other just did an entire format revamp, often with a complete change in imaging and station slogan: "Goodtime Oldies" KODJ, focusing on 50s and 60s, lasted only two years and change (March 2, 1989 to July 12, 1991) before dumping the 50s in favor of adding early- to mid-70s as "CBS-FM" and also played more rock crossovers than KRTH. That lasted about the same amount of time as KODJ (until September 10, 1993) when they went hit-oriented Classic Rock as "Arrow 93" (which, BTW, took them immediately from #18 to #3 in the 12+ Arbtitrons) and then morphed into today's "Jack" format a little over a decade later, on St. Patrick's Day 1995.
So 93.1 went from a traditional Oldies format through a gradual moving forward to a format heavy on modern rock in the space of (literally) only six years. A lot of stations went much more quickly; KRTH was mostly 1964-69, with a few early 70s titles, during most of the period I outlined above and it wasn't until 1996 that the oldest titles were removed from the library and it was during Jhani Kaye's tenure there that the format finally became 80s-centric.
A lot more stations made more dramatic shifts, in some cases moving to formats totally disparate from either Oldies or Classic Hits; starting in the 1990s we saw many AMs drop Oldies for talk-based programming, and only the rule change about FM translators being able to have an AM be the "originating station" slowed that tide down.
There are relatively few Oldies stations on standalone FM signals these days (I know because I recently did some research into that) and most of those don't go farther back than the '70s except for "heritage" bands such as the Beatles, Rolling Stones, and Beach Boys. There are virtually
zero Oldies stations playing the '50s that aren't AMs, with or without translators.
And a huge chunk of Oldies stations are running Scott Shannon's format, which will likely go away as soon as he tires of doing it. (He doesn't need the money, so it's a question of personal satisfaction
vs. operational and legal headaches.) Add to all this that the audience is
literally dying off, one listener at a time, and you are going to see a lot more Oldies stations bite the dust ... probably literally as towers fall on real estate about to be redeveloped.
The fact that a small minority of kids like Oldies is not going to save the format. It simply is no longer generating enough revenue to pay the bills and stay on the air.