i don't think this is the case. the mind-body conditioning to be able to release power (fajin) like the IP/IS folks is the same as be able to manipulate (aiki/huajin) other folks' power like what Ikeda sensei shown. it's a matter of usage. the conditioning is the same.
from my point of view, what Ikeda sensei shown were a bunch of sentences to demonstrate a language. whereas, the IP/IS folks shown the alphabet, vocabulary and the grammar rules to construct sentences and paragraphs. once you have that, you can write essays in any style (karate, judo, kungfu, aikido, ...etc) you want.
You could be right... not sure yet, but maybe. All I know now is that I can do pretty much everything Ikeda Sensei is doing. But it won't feel like what the IP guys are doing. I have felt both and Ikeda Sensei and Saotome Sensei feel different. Perhaps it is simply because they wish it to feel different. But I have not seen either one do the kind of conditioning exercises that the IP guys do so I am assuming that there is relationship...