Why do you think it's not in use? Microchip calls it a "capacitive touch sensor" IC on their website. Plenty of phones have that.
I haven't seen that. Why hasn't it happened yet?
edit: Anywho, let's check the Microchip website. They don't call it what you said. There's no capacitive touch on its page, just the title. It's all 3D e-field. I think you must have got the wrong chip. Where did you see it?