You seem to be saying that as you open the lens up the light from the outer parts somehow only contributes to the OOF areas and does not contribute to all areas??
I may not be getting what you were trying to get across though and perhaps we are talking at cross purposes.
I made that statement as the 'then' part of if an if-then clause. It's clearly false, and the point was that if the 'then' part is false, then the 'if' part is likewise false.
Light falling at extremely oblique angles from a lens with a very wide aperture is detected at progressively reduced efficiency by smaller pixels. That doesn't make the out of focus light at those wide apertures less out of focus.
Why would it make out of focus light less out of focus?? But if it didn't capture some of that then you do lose just a little blur along with overall brightness across all parts the image in focus or not since the outer stuff arrives everywhere in focus and out of focus.