Thanks for the interesting link. But I don't see your point. Pr. Kano is doing a standard Uki Goshi, which is executed with Nage and Uke having their feet and hips parallel, and a horizontal twist of Nage's hip in contrast to O Goshi (a frequently confused technique) where the hip movement is rather vertical. In fact O Goshi is closer to Koshi Nage than Uki Goshi, which was Pr. Kano's favorite technique by the way.
I have seen Uki Goshi taught at "some" aikido dojos under Koshi Nage appellation, but it is just an adaptation from Judo, just like Ippon Seoi Nage that some instructors like to use against a Yokomenuchi (we do use a variation of Kokyu Nage which looks very similar to Ippon seoi Nage but does not involve any Koshi).
But I might be wrong