People don't seem to realize that FFXIV is a Japan made game and thier laws governing copyrighted material are probably different than the US. While you are allowed to use other audio with most anything else (unless the audio's artist/label complains) it might not be the same in Japan. SE is just covering their own legal butts in case someone wanted to sue them. I seriously doubt it has ANYTHING to do with a small glitch that let's you be stuck in an emote.
