Well the fact that it has its own ending may be regarded as filler, but not really. The anime was beginning to catch up to the manga, so, instead of making shitty filler episodes to give the manga some time, they decided to give the anime its own unique ending. The creator of the series, Hiromu Arakawa, said that she wanted for this as well because she didn't want to see the same thing... lol now shes doing it again to do the whole storyline again.
Anyways, i'm really excitd for this, im just hoping that the directors don't mess up such a masterpiece. it would really be a shame