It seems like movement would be effective for averaging out random noise, but the described process isn’t for eliminating random noise, it’s for eliminating persistent hotter pixels on the sensor.

Indeed, and in fact the pixel does exactly the same dark frame trick to identify hot pixels. I don't know that it takes as long though - perhaps it's hidden by the fact you can keep doing other things while the photo is processing.

It cannot do the same thing as an a6000, as it lacks a physical shutter.