is bleach episode 252 filler?

As Kōga pushes Captain Byakuya Kuchiki's blade up, they leap back from each other as Muramasa, Ichigo Kurosaki, and Rukia Kuchiki watch. As Ichigo expresses shock at Byakuya's sudden appearance, Rukia tells Byakuya to be careful.

Noting Byakuya is wearing a windflower-silk scarf and a kenseikan, Kōga states Byakuya is from the Kuchiki Clan, prompting Byakuya to tell Kōga his name and reveal he is the 28th Head of the Kuchiki Clan. Noting Byakuya is from the 28th generation of the Kuchiki Clan, Kōga states a great deal of time has passed since he was sealed away and says Ginrei Kuchiki must have died by now.