User blog comment:Miskos3/Fairy Tail Episode 241: Tartaros arc: Devil Reincarnation, Review/@comment-7418318-20150711205009/@comment-2125188-20150711210513

What I think is they originally wanted all the 'parts' to be separate, but when they got to the end of part 1 they couldn't fit everything properly, so they just started adapting it like any other arc.