Interesting... however, in an interview with Yamaguchi Sensei's famous student, i.e. Endo Sensei, I did recall a strong preference for empty-handed techniques... I remember the interviewer asking him about weapons training, and Endo Sensei replied there was still so much to be done with taijutsu... maybe he wasn't part of the group that took to weapons in a big way?
I know the interview you mean. Yes, Endo is an exception among the Yamaguchi deshi in that he doesn't emphasize the sword or show that his taijutsu derive from the sword. (Unlike a Gleason or a Yasuno, for instance.) I don't really know why Endo is different, though of course we know that Endo is a relative latecomer to the group, in that he only chose to follow Yamaguchi after spending ten years in Hombu Dojo following other teachers like K. Ozawa. As opposed to a Yoshinobu Takeda or Yasuno, who were with Yamaguchi since almost the beginning of their aikido careers.