is one piece episode 977 filler?

None of the people who promised to arrive at Tokage Port arrive, not even Luffy. The Nine Red Scabbards realize that since they took over Udon, Kaidou's forces will be informed of their presence soon.

So, they have no choice but to set sail for Onigashima immediately, getting on a small rowboat to traverse the stormy waters. This marks the third time that their plans have been leaked to Kaidou's forces.

Kin'emon deduces that there must be a spy among Oden's retainers. Kaidou hinted at a spy before but Kin'emon did not believe him until now.