I don't understand what this means. I see they've included all the alternates but they've done that before. Why would this opportunity not exist in the future?
Because someone might reclaim some rights, some douchebags might extend copyright laws, Mosaic (or the world at large) might go under... make your pick
Let me put it another way: What does "it was imperative we issue them in complete form" mean? That they're using all takes? What is a full performance?