The composition of O-Sensei's teaching of ancient Shintoism was based upon the Kojiki, interpreted under the strong influences of Deguchi Wanisaburo of the Omoto Religion, who was the spiritual teacher of the Founder.
"Wanisaburo" is how one normally reads Onisaburo Deguchi's given name in Chinese characters. This is probably a bit of a stretch (or not) but when I read or hear "Wanisaburo" my guess is that the individual read about Deguchi, ie. did not hear it. I have read this quote of Chiba Sensei's before and it makes me suspect that his knowledge of O'Sensei's spirituality, to some degree, does not come directly from the Founder.