is one piece episode 729 filler?

Doflamingo causes part of the cliff around him to fall away, and the citizens of Dressrosa run from the falling rubble. They run past Luffy, who struggles to stay off the ground, and some stop by him, but run away due to not wanting to get involved with Doflamingo.

Luffy falls to the ground once again, but is suddenly grabbed by Gatz, who recognizes him as the gladiator Lucy from Corrida Colosseum and asks Luffy if he remembers him.