is one piece episode 521 filler?

The episode starts in Grove #17 where the Thousand Sunny and the Straw Hat crew (excluding Luffy, Zoro, and Sanji) is. Rayleigh gives Nami information about the weather in the New World.

They are all excited to see how Luffy has evolved in 2 years of training. The crew is afraid that Luffy might have caught up in some trouble.

They want to inform Luffy, Zoro and Sanji that they must go to Grove #42 and set sail for the New World. Chopper has something on his mind in case they are caught in trouble.

Meanwhile, Brook gets away with the Rosy Life Riders, from the Sabaody Dome.