It looks like they made the miniaturize the pixels to increase contrast and make more room for pressure detectors. However, since blue pixels can't be made as bright as the other colors they have to be bigger than the other pixels.

Has anyone actually confirmed that the display has physical strain/pressure sensors, or is Apple just using the diameter of the capacitive touch point as a faux-pressure calculation?

Yeah, I find the pressure sensitive API in Android is good enough, it just uses the diameter of the touch. It's good enough for varying my pen strokes in a sketching app.

I haven't tried a Note with a true pressure sensitive pen though.