To me it seems more sensible to store information relevant only to this OS in a specific cache somewhere within that OS. It would even make cache-like functionality such as evicting old entries super easy.
In 1970 it already was not true that one could treat all filesystems the way Unix did, but it certainly isn’t true anymore today.
For most of these files, this isn’t information that can be reconstructed, so caching isn’t an option.
Also, the information has to move with the disk, if it is moved to or mounted on another system.