Age of masters

Many record labels transferred their analogue libraries to digital to preserve the master.

Transfer of analog to digital is OK for streaming and digital releases, but it make no sense for vinyl releases, lacquer cut direct from an old mastertape is what we need on vinyl. Master tape rules anyway.

@chakster 
That's very true. But in some cases, they dare not run a decades old master tape with missing or peeling oxide, or edge damage on an ATR.

If the mastertape is damaged, lost or burned in fire all we need is original record (not a reissue from digital copy)

I have about 100 production master tapes in my collection - these would have been copies taken straight off the original stereo mix down by the record company and sent across the world to record pressing plants. Local record pressing plants would often cut their own lacquers, hence the variation in quality between different pressings.
If a record company decides to remaster an album, they will use the best available tape - multitrack session tape, original stereo mix down, production master - depending on the availability and quality of the different "masters". If they don’t have tape available, they will use the digital archived copy.
My tapes are all 30-50 years old and sound magnificent. But just like the record companies, I archive my production masters onto new 15 IPS 1/4 inch tape as well as a 192/24 digital archive copy. I play my dupes and store the production masters safely.