is one piece episode 734 filler?

The citizens of Dressrosa run away from the parts of the city sent flying by Doflamingo's impact with the ground, and Rebecca stares up at Luffy in awe. She remembers meeting Luffy in the Corrida Colosseum by the statue of Kyros and later revealing her intention to kill Doflamingo at the prisoner gladiators' cell.

Next to her, Viola remembers submitting herself to Doflamingo ten years ago in order to save her father's life, and when the Straw Hats came to Dressrosa ten years later, she told him that she would trust in the Straw Hats despite them being pirates.