is one piece episode 659 filler?

While Rebecca continues her fight in Block D, the Thunder Soldier explains to Usopp, Franky and Nico Robin, how the former king Riku lost the faith of his people and, eventually, the throne. Dressrosa used to be a fairly poor country but the people were happy and grateful for their king, whose family had managed to keep their land out of war for a whole 800 years.

One night, however, ten years ago, Doflamingo appeared in the king's chambers.