is one piece episode 909 filler?

Heading to the ruins of Oden castle atop Komachiyo, Luffy grows restless and inquisitive after hearing Law, Kiku, and Zoro mention the existence of ghosts residing at the castle. The group notices that they are being chased by a shadowy beast, and Zoro volunteers to fend it off while the rest continue on.

Zoro engages the creature, a giant white tiger wielding a sword in its mouth. In the Flower Capital, the scene shifts to a school classroom in the middle of a lesson.

The young students are learning about the strict isolationism of Wano Country, as well as the downfall of the Kouzuki Family.