Based on my own experiments, it's not the age of the recording, it's the age of the DAC.
New DAC's perform much better with plain Redbook than old dacs, but still may show slightly more sparkle with upsampling.
Does IN Player Upsampling Benefit Older CDs More Than Newer CDs?
Assuming the mastering is good on both -in your opinion-does In player Upsampling (Denon DCD-A110,Marantz KI Ruby) benefit older (early 90s CDs and older) as opposed to newer (early 2000s and later) ?