He didn't as far as I know. The two kata I believe is their respective interpretation of the variations of the kata O-sensei did many time (hence the very much similarities of the two).
I'm faithful to Saito ha aikido
but I would say that 22 kata (as Tohei did it) is probably just as close as the 31 kata (as Saito did it) to how O-sensei did his generic misogi/kata.
Actually watching Tohei do 22 kata (with speed!) looks way more like what O-sensei did
at the footage I've seen at least, then todays broken down 31 kata. I have actually only seen Daniel Toutain do 31 kata close to how Tohei do 22 kata (close to how O-sensei did kata).
But I might be wrong.