is bleach: thousand-year blood war (bleach: sennen kessen-hen) episode 29 filler?

With a dark aura manifesting behind him, 13th Division Captain Jūshirō Ukitake announces to the other Shinigami present in Kisuke Urahara's laboratory that he will be taking the dead Soul King's place. Surprised by this, Urahara questions if it is even possible, but Ukitake merely asserts that he will explain later as he discards his captain's haori and strides forward to the center of the platform in the middle of the laboratory before removing the upper half of his shihakushō as well.