User blog comment:Omega natsu2/Episode 200: Drops of Time, Review./@comment-2214433-20140920111140/@comment-5426822-20140920143503

It's probably the makes with an additional new plot. The tweet gives the design of a new character that does not appear whatsoever in the original four omakes, so I highly doubt it's just those. It also states that Mashima will be doing the new character designs and the rough plot, why would he be doing that if the only "filler" we're getting is something were the characters and plot are all ready determined. It would make no sense.