So, the theory is that no one can "authoritatively state what Ueshiba was doing". I think that's fairly easy to disprove once the research is done
For me, this isn't really the important question. As someone pointed out, it's still just an appeal to authority, which to me isn't really much of an argument for something - it kind of feels like changing the subject (I know it isn't intended that way). It simply doesn't really do much to help me figure out if something is going to be important or useful to me
in my own life. It's like trying to sell a product by telling me that a lot of really cool people use it -- I've never found those kinds of ads to be particularly relevant to me, or even to particularly pique my interest. Fundamentally if something's interesting it's because it's interesting itself.
In the end, for me whether something interests me enough to make an effort to learn more about it or not is going to come down to the actual content. Unfortunately this can be a barrier in this particular case since the things being spoken of are kinesthetic and it seems to be pretty difficult to have a verbal discussion about them, particularly without prior knowledge. So I guess I do see why discussions often just devolve into appeals to authority... But sadly the result is that the discussions can be kind of boring and off-putting to someone who isn't already fascinated by the subject.