I may be able to provide a reasonable guess in response to you. Specifically, the part regarding Ikeda Sensei and the Yoshinkan.
Back in October 2000, the Aikido-L Mailing List held a multi-style seminar that we asked Ikeda Sensei to host.
(We've been doing this every year since 1998, and rotating them around the country. Typically, we'll have 5 instructors from 5 different styles of aikido each teach one class over a 2-day weekend. See http://www.aikido-l.org/seminars/
We generally draw from the members of the list for instructors, with the exception of the host dojo, who is always invited to teach. So, Ikeda Sensei, as host, was there for the entire weekend.
As it happened, one of the other instructors that year was Yoshinkan's own Philip Akin. I expect you know (or know of) Philip, yes? Fifth dan, trains under Kimeda Sensei in Toronto.
From my own observation, Ikeda Sensei not only taught his class, but made a point of training in every other class, as well. Not as "host" or as "most senior person there", but as student -- trying new things, learning different approaches, experimenting with everyone's methods. He was an absolute joy to train with!
During his class, he talked at some length about the benefits of trying new things. He encouraged us all to sample everyone's
different interpretations of aikido.
The things we liked, we should make a part of our own aikido, and for the parts that didn't suit us, well, there was no harm in trying.
He was extremely open to trying new things and encouraging to us to do the same.
I don't know if this was the most contact he'd had with the Yoshinkan, or even if it was the most recent. Nonetheless, he and Philip seemed to hit it off rather well, and both very much enjoyed the spirit and joy that each other trained with.
That may have been the seed for his comments regarding Yoshinkan.
Or, I could be wrong.
Maybe Jun has a viewpoint on this.