my take on old ra-4 paper
My experience is that if it is older, or has not been cool stored, it will loose red sensitivity. You will dial more yellow and magenta into it than you ever have before tocompensate. It can still be used.
Once really old, it will start to loose vitality in the colours, and may even take on an overall yellow stain. Ektaprint/2 does this for sure, but that paper is definitely 'quite old' by now (though I still have some for things like clean out sheets in my roller transport processor)