I think I disagree. Are there any students who ever have "every" part? Particularly if we consider the spirituality of O Sensei? We don't all have to have IP in order to enjoy the rest of Aikido. I think that was the point...though I could be wrong, of course. It happened once before...although in retrospect I may have been mistaken.
Maybe "all" is too much, but I think that are a number of parts that just can't be missing in order for it to be Aikido. That doesn't mean it's bad - just something else.