Anne Marie Giri
I have plenty confidence in Peter Bernath, Harvey Konisberg, Clyde Takeguchi, Andy Demko, Donovan Waite and Claude Bertiaume to lead our organization. They are not only incredible aikidokas but leaders as well. They are fully capable as shihan and 7th dan to lead our organization. (They are not SINO - Shihan In Name Only or Shichidan In Name Only. They have earned these ranks and have the skills and leadership abilties to go along with them.)
I think the USAF learned a hard lesson after Tohei Sensei and later on when Kanai Sensei passed away. We are already dealing with the consequences of losing our leaders and are taking steps to prevent the chaos that follows when a strong leader passes.
I also don't see this happening in Chiba Sensei's organization either. He's taken quite a big step forward with his Birankai Organization, which is now recognized under the Aikikai umbrella - as are their shihan.
While I am not saying it couldn't happen, it would basically be a first if, after Yamada, Sugano, and Chiba Senseis are gone, the next generation managed to keep things together in a harmonious whole.
Usually, once the big guy(s) is gone, all of the different aspirations of the various individuals start coming out and they find that they have widely differing ideas about where things should go...
Mark my words, I could easily see the Aikikai Hombu dojo thinking it should send a new generation of Japanese teachers over to preside over the folks you mentioned, despite their ranks and Shihan status. If I had money to spare I'd bet on it...