is one piece episode 889 filler?

Sabo and other elite Revolutionary Army officers hide underground as Rosward and Charlos leaves the area. Having learned the tragic truth about Kuma, Sabo thinks about Kuma's actions.

During the Straw Hat Pirates' first adventure to Sabaody Archipelago, they were faced against Kizaru, whom they had no hopes of beating. Although apparently siding with Kizaru, Kuma sent the Straw Hat Pirates away to separate islands so they would not be killed.

The time the Straw Hat Pirates spent apart allowed them to become stronger when they reunited two years later.