And the irony here, is that without this copyright issue, these tracks might not have been releases at all.
The purpose of copyright is to have people produce, and in extension release their work. In this case it's quite easy to argue that the copyright laws helped directly in getting this released. Had there not been this 20-year extension rule, most likely they'd have let the copyrights expire and possibly simply dump the tapes in the garbage bin, only to be lost forever.
Oh, and there is no **AA organisation involved. From the shortish terms you should've known that this is not US copyright. This is EU copyright.
By the way, I'm not trying to argue that this 50/70 year thing is good or bad. Just trying to show how stupid GP's comment really is - if the way it's written half in the subject half in the body didn't tip you off already.