Sorry to differ, but the Koshiki No Kata is an official kata in the Kodokan judo syllabus. It's a 8th dan kata at the Kodokan. My Kodokan judo & koryu jujutsu teacher in Tokyo did the Koshiki No Kata for his 6th dan as a specialist kata.
It is very much an official kata of the Kodokan. Not to mention every official kata manual for the Kodokan contains the Koshiki No Kata as well as the Ju No Kata, Kime No Kata & Kodokan Goshinjutsu.