Something that recently reminded me of moving goalposts on old music.
I was listening to B.B. King's classic 1965 album "Live at the Regal" and he introduces one of the songs as "real old blues." Electric blues wasn't 20 years old at that point.
This also recently caught my attention:
Released in 1971 https://en.wikipedia.org/wiki/Good_Old_Rock_%27n%27_Roll
What 12 year old songs are the "Golden Oldies" of today?