I see how this would play out... They would just make the front face of the cabinet itself thicker vs. making the grill thinner or cutting into the current cabinet. You wouldn't gain any reduction in total thickness as that would interfere with the sound of the speakers.
I think that flush grills work well for those of us that keep grills on, but then you have the people that don't use the grills, and it might look strange for them. Not a win-win situation for everyone, so probably won't change unless they DID just make the grill thinner.
