is demon slayer: kimetsu no yaiba episode 47 filler?

Yoriichi Type Zero is destroyed at the end of Tanjiro's training, but a sword from over 300 years ago appears from inside. Kotetsu gives Tanjiro the sword; however, it is badly rusted.

At that moment, Haganezuka appears and takes the sword with him to perform a grueling whetting process handed down within his family line. Meanwhile, the presence of demons is inching closer to the village...