I don't know anyone who doesn't think there is more to aikido than what they know, shihan or otherwise. Also, I don't know anyone in aikido who doesn't think we should develop ki and kokyu skills, by the way. The differences of opinion, is what is most usefull and what is the best way to do achieve it. For instance, at what point in development should one primarily focus on such things and when should it be more of a secondary concern given many conditions (like your level, the ability and availablility of a qualified teacher, your training partner's levels, your personal goals for what you are trying to achieve, and your various teachers goals for teaching you).
We're talking about the information that Tohei and others had to go and deliberately seek out.... none of them just "knew it" because they were Japanese, Swedish, Chinese, etc. Insofar as someone re-discovering it on their own, I wish them well and a fond adieu.
?? If the way to develop those skills is specific like the "certain way to repair an automobile engine or to solve a mathematical equation" and human bodies haven't changed much, I'm still not persuaded by that line of though. I made a point about Zen Masters rediscovering Zen. They didn't "just know it" without seeking it either and I'm sure it was also a non-trivial endeavor. How could one even compare those discovering how to develop ki and kokyu skills to becoming a Zen master (and trivialize one enough to dismiss it) unless you've done both?! Lastly, if discovering how to develop ki and kokyu skills is so complex that it cannot be re-discovered, I suppose I wonder how anyone initially discovered it.