You're assuming baby boomers all want to listen to oldies, but they don't. I'm 61, I'd listen to current CHR before I would listen to an oldies or classic hits stations, although I really prefer country, both old and new.
There are some stations playing music for boomers, but they don't have very many listeners.
One is "Cruisin' 1430" in Denver, owned by Entercom. They have a 0.6 6+, so not even very many boomers could be listening to them.
Here's a sample hour of their playlist:
I Got You (I Feel Good) James Brown & His Famous Flames
Did You Ever Have to Make Up Your Mind? The Lovin' Spoonful
There's A Kind Of Hush Herman's Hermits
Stay Maurice Williams & The Zodiacs
Brandy (You're A Fine Girl) Looking Glass
Gimmie Some Lovin Spencer Davis Group
Singing the Blues Guy Mitchell
Dancing in the Street Martha Reeves & The Vandellas
La Bamba Ritchie Valens
A Summer Song Chad & Jeremy
Ruby Baby Dion
I Can't Help Myself ( Sugar Pie Honey Bunch) Four Tops
A Groovy Kind of Love The Mindbenders
Dream Baby Roy Orbison
That Boy Beatles
Denver's KEZW Cruisin 1430 is pretty much a one man show that being Rich Crandel. Besides the morning show he also does sales for KEZW too. Most of the spots on 1430 are probably from Rich. The man even put his grand kids on the air some years back. Rich has been there for many of years and I don't know why he is still there other than maybe he does a good job selling for 1430 that and a good contract. Anyway in the event Rich leaves 1430 you could probably bet the farm that the oldies will leave 1430 and here comes Denver Broncos talk 24/7.