There are several things that could be highlighted in the above statement, but the first is the strange effect of retrospect when looking at information about these skills and knowledge. "One of the interesting things I found as my own skills progressed..." That is the crux of it. One could have read Kisshomaru's descriptions for any length of time, but until "one's own skills progress" they are meaningless.
Reminds me of the old Mark Twain line: "When I was a boy of fourteen, my father was so ignorant I could hardly stand to have the old man around. But when I got to be twenty-one, I was astonished by how much he'd learned in seven years."
On Mike's question about "ki" in the aikikai after Tohei: It has always been my impression since my early days training in the 80s (ie. before the internet when hearsay and oral culture was king) that "ki" curriculum was tainted because of its association with Tohei. My impression was very strong that "ki" was Tohei and so out it went with Tohei no matter its utility or lack thereof.
Well, I can see that as a possibility. However, for some reason Tohei felt like he was showing the uchi deshi new information (which he'd learned outside of Hombu Dojo so therefore it wasn't in Hombu Dojo, right?). So regardless of the stigma of Tohei, there's still something interesting going on that I don't think we see the full picture of at the moment. There are too many factors. K.Ueshiba could have had some level of academic understanding but not much skills, or etc., etc.