That what I would have thought. Except something is happening here that causes things to be different.

Simply filtering out antibodies should not have any effect on organ rejection, since the antibodies are just regenerated, yet for some reason it does.

The immune system has mechanisms to rein in self-reactive immune cells (look up anergy). My guess, in broad strokes, is that the immune response in the absence of antibodies results in a sufficiently weak immune response that the cells that do react are flagged as "false positives" and become anergized. Then when the antibodies return later, tolerance has already been induced among the T-cell population, so the B-cells don't get activated, and the immune response remains low persistently.

So that would mean 'yes' it might help with auto-immune disorders. (But no to childhood vaccines.)

Possibly, but it would depend a lot on the specifics.

Maybe I'll get in touch with the researches and ask if they might be willing to study it.

Edit: I sent them an email asking.

The problem with the autoimmune case, though, is that the immune system has already raised and activated specific T-cells and B-cells against itself. In contrast, your immune system can't possibly have specific defenses against a new graft, only general defenses. It's possible that this technique only prevents the formation of immune memory on initial exposure to a foreign antigen but cannot erase that memory once it is formed.