is one piece episode 755 filler?

As Zou begins shaking due to the upcoming Eruption Rain, the Heart Pirates climb on trees while Luffy joins Wanda and Carrot atop Wany's back. At Kurau City, the concerned Straw Hats wonder why Zou is shaking.

Wany starts to run as the elephant carrying Zou on its back, Zunesha, lifts up its trunk and spews out a large volume of water onto Zou. The Straw Hats run away, but realize that it is too late to avoid it.

Meanwhile, Wany, Wanda, and Carrot are submerged in the raging flood, and eventually emerge from it; they then realize that Luffy has fallen off.