Board Thread:Episode Discussions/@comment-25626003-20150809235106/@comment-2140588-20150830101719

^What Elve said. Though there are some manga artists, who actually have some input when it comes to anime, including filler content ("Fairy Tail" is the first thing that pops to mind), but the fandom still consider them to be non-canon. Kishimoto hasn't revealed any connection with Studio Pierrot, involving filler content 'tho, as far as I'm aware.