People seem to be asking, 'what did o'sensei add to daito aikijujitsu, to make it aikido?
The answer is Tai no henko. O'sensei added that, essentially invented it. This never existed in the old style aikijitsu, if they use it now, its because they stole it from aikido. O'sensei was fond of saying that every single technique in aikido uses tai no henko, or, at least its essential action, the circular turn. I also believe that he 100% took this move from Japanese sword styles, not chinese styles, as some have suggested.
I'm not inclined to think that Sagawa (who practiced tai no henko in a slightly different form) would steal anything from Ueshiba, if only because of Sagawa's massive ego and his dislike for Ueshiba. Kodokai also has a kind of tai no henko.
What's your reason for thinking that it didn't exist in Daito-ryu?
I don't he think he took anything from from Chinese styles either - or rather I think that the Chinese training paradigm entered Japan from China a long time before Ueshiba and that the received the Chinese paradigm from Japanese sources.