is one piece episode 873 filler?

With Ichiji, Niji, Yonji, and Reiju between them and their targets Sanji and Luffy, the Big Mom Pirates open fire on the Vinsmoke siblings. However, the bullets harmlessly bounce off of them, and Ichiji tells Sanji to take Luffy off the island, with the Vinsmokes claiming the Big Mom Pirates as their prey.

Oven wonders how they are here, having heard that they were defeated by Nusstorte's army. The Vinsmokes reveal that they defeated the army and tossed them all into the water, stunning Oven's army as well as Mont-d'Or and Niwatori, who are overhearing the exchange through Den Den Mushi.