lets say stickerless cubes stay illeagal until the point when 2/3rds of the competitors are using the ShengShou 7x7 and 1/3 are using the V-cube 7 which is still legal.
At this point, an illegal cube (V-Cube 7) is now legal due to the fact that there are not many cubic 7x7s, even after they are outnumbered 2 to 1 to cubic cubes.
Many people use Dayan guhongs, zhanchis, lingyuns, and most likely will use the new Dayan 6. All those cubes are available in white, black, and stickerless. That means, the most popular brand has 1/3 of its cubes stickerless.
If this happened, 1/3 of 7x7s are illeagal because they are pillowed, but the rules were changed to let them compete, and 1/3 of all 3x3s are illegal because they are stickerless. Why would we not have stickerless legal?