User blog comment:Miskos3/Fairy Tail Episode 241: Tartaros arc: Devil Reincarnation, Review/@comment-24228963-20150711160527/@comment-2214433-20150711161253

I think they're the property of the old studio, actually, so maybe the new one can't use them. But they were never in the manga, so the new studio is just following the manga more closely.