Okay, now on some of the reprinted MGM DVD's, after the studio pretty much died off, I've noticed some of the DVDs in stores have both MGM and Sony (or some other company like Fox and TWC) on them. My question is, would be okay to do since it's being done on professional DVDs?

That would be up to the creator. If he or she (do we even have women around here?) thinks it important enough to use the new method or just go old school, that would be on them.