I think I understand what you are saying, but the thing that puzzles me is that I first mentioned this in connection with my seminar exposure to Abe Sensei, at the invitation of Shaun Ravens. Fred Little was there with me, and it was his suggestion to move the shoulder blades together during kokyu ho. I also mentioned that in relation to some other teachers as well, I believe.
Gerno H. also mentioned this in relation to Abe Sensei. I've seen mention of it by other aikidoka as well.
So...with all of the aikidoka that have given me this input, and me reporting that in my blog and postings, and aikidoka confirming that practice online....I am puzzled to hear statements like "I haven't heard this in relation to aikido" from long time aikidoka.
Perhaps you are correct, it just takes time to sink in. I can tell you that physically, it is taking a LONG time for it to sink in with me.
I've trained under Saotome Sensei for over thirty years... not one time did he ever talk about these body centered details. In his Aikido it is clear that he does these things but really doesn't think of them in any way except holistically. If I ask him about them, he often responds "yes" or "of course".
There are Aikido teachers who simply don't know these things, there are Aikido teachers who do them but aren't really aware that they do them (they are so ingrained), there are teachers who both do them and can explain exactly what they are doing (like Abe), and there are even teachers who are not yet able to do them but know they are there and can at least tell their students what they are "trying" to do. It's a whole range.
This isn't any different than therapy and counseling... nothing can possibly change until you know and admit you have a problem. There are plenty of folks who don't want to know about this stuff; they are quite happy doing what they have been doing for years.