Bill, it is my understanding that all records are pressed with a thin coating of a mold release agent applied to the stamper. If the stamper is not so treated, the LP's resist detaching from it after the cooling phase of pressing.
This seems to be true, but according to what I've read on Vinyl Engine, not every pressing plant uses it, and if it's used, it's a judgement call by the operator on when to use it. RTI was one example given as not using it.
Release agents are used for tool and die parts in manufacturing, wherever parts are being molded.