"...the 80's music is approaching the 19-28 year old timeline..why not call them oldies too??"
Isn't "oldies" a dirty word now? I'm surprised it hasn't been put on the list of the words Radio-Info won't let you say. ;D
Actually, the word "oldies" is not that...uh...old. I believe Art Laboe popularized it with "Oldies but Goodies." But in the 60s and 70s, mainstream top 40 stations called them "goldens" or "solid gold." The first two oldies stations in the SF Bay Area were KNEW in the 70s, which played "California Gold," then KSFO/KYA-FM in the 80s, which played "Rock and Roll Classics."
I've noticed the K-Earth still lets the dreaded word slip onto the air on occasion, but everywhere else, it's "Classic Hits" now, isn't it?