Referencing the thread, Which Aikido Are You Doing:
We can start to get a picture that all the students of Ueshiba *changed* what they'd learned. At least in outward form. So, technique-wise, Tomiki, Shioda, Tohei, etc all look different.
But, from this thread and from the thread, Exploits of Ueshiba Morihei, and the thread, Push Test with Ueshiba, it's not hard to see that Ueshiba was still doing the core component of Daito ryu -- the aiki. Other Daito ryu greats did the same thing.
And if you do a little bit of research, you find that the schools of Daito ryu (Hisa, Kodo, Sagawa, etc) all do different techniques, too. Yet, they are Daito ryu. But, the greats kept doing similar "magical" things.
The only common reference between Ueshiba, Kodo and Sagawa is Sokaku Takeda. What Takeda did, so did his students.
Doing some more research, you would find that Takeda and Ueshiba were at some point very close. At some point, Ueshiba and Deguchi were close. And yes, something happened. We speculate on what. But, for the idea I'm putting forth here, what happened does not matter. What matters is what happened *after* the relationships that Ueshiba had went away.
Ueshiba distanced himself from Takeda. And in doing so, he distanced himself from the name, Daito ryu. And as such, he changed the name of what he was doing. We can recall that at one point, Takeda changed the name to Daito ryu aikijujutsu. And we know that Ueshiba taught aikijujutsu. It's not a leap to see that Ueshiba changed the name to aikibudo, dropping Daito ryu altogether. And when the organization said, we want to call these arts, aikido, it wasn't that great of a leap for Ueshiba to agree. It's what he was doing by then, anyway. He stamped the ground and exclaimed "Aiki? I am aiki!" when he was older.
Tying up another point above -- techniques. All the greats around Takeda said that the art was formless. Thousands of techniques. Techniques were created spontaneously. It is the very nature of what Ueshiba said, "I am aiki!" that creates takemusu aiki. It is the nature of Daito ryu aiki that was passed from Takeda to Ueshiba, Kodo, Sagawa. (I use the big three because they are prime examples.)
This is why every student that traces their lineage back through either Daito ryu or Aikido has a different outward expression. Tomiki, Hisa, Shioda, Okamoto, Kondo, Tohei, etc, etc, etc.
Ueshiba, near the end of his life stated it so simply, "Aiki? I am aiki!". He was. And he built it from Sokaku Takeda. Even to the end, Ueshiba was Daito ryu aiki, but because of something that happened between him and Takeda, he quit referencing his teacher's art -- Daito ryu. But he never stopped being it.