is bleach: thousand-year blood war (bleach: sennen kessen-hen) episode 1 filler?

In the Shinigami Research and Development Institute, 12th Division Captain Mayuri Kurotsuchi inquires about the status of the Shutara Scale, prompting his 3rd Seat, Akon, to relay that it is at category 4 as the two of them ride an elevator down through the building. When Mayuri admonishes him for taking so long to report this, Akon apologizes and explains that they have been able to handle minor instances of this in past years with only slight adjustments, which led him to not take this to Mayuri until it became serious.