Y-107 in Columbia/Jefferson City has been doing a "Retro Lunch" for at least 15 years. It's not a rare feature for a CHR, even if it's less common than it used to be. While it won't make my 12 year-old niece listen (she's still a Z-107.7 fan), she's not in their target audience either. They're after the 25-34 year old women with the retro. My wife is a tad younger than I am, and the 90's and the first five years of the new millennium are still the glory days of music to her.
And, yes, KNOU has always been a more adult skewing CHR. Even though my wife is exactly who 96.3 is after, her ears gravitate toward 100.3 as soon as we get into its listening range. She flips between 100.3, 98.1 and 99.1 in St. Louis, and she'll go to Fly or The Pulse on SXM if they're not playing what she likes.