No, I am saying the noise is decreased by downsizing, assuming averaging of pixels instead of simply throwing them away. The width of the histogram (Standard Deviantion) of a uniformly colored subject in uniform light is a measure of noise. That does decrease with downsizing.
How does that differ from taking the 8Mp image and downsizing it to 5Mp in an image editor with an averaging resample mode?
I think everyone would agree you see less noise if you downsize the image or view it smaller. But that isn't the same as having the noise characteristics of thelower densitysensor.