Can you reference the regulations that indicate why 2x2 is different from 7x7?
The pillow version for 2x2 Cube came out long after the normal version. The pillow version for 7x7 Cube has been the standard for a couple of years now.
Also, the advantage for a 2x2 Cube seems to be higher than for a 7x7 Cube. Although I cannot confirm that scientifically.
I'm guessing the majority of competitions have allowed pillowed 2x2's since this wasn't clarified for 6 months.
I am surprised that there were competitions where the pillowed version for 2x2 was allowed. In the competitions that I delegated I have only been asked once whether a pillowed version could be used.
The regulations are already clear on this subject. And we have had similar cases with the transparent cubes.
But with US Nationals very close, it would be bad to change it now.
It would be worse to officially accept it now. Also, there is still enough time to prepare a good non-pillowed cube.