I remember that. I don't remember you winning.
Anyhow, one example doesn't prove a point, because sensors are designed things - it's not the case that each example exactly follows a rule. It seems to be the case that most image sensor design houses uses essentially the same pixel design (that is transistor layout) across a range of pixel sizes, just varying the 'photodiode' area. In that case the per-pixel read noise is the same across that range of sensors, which causes the higher pixel count ones to suffer from slight higher read noise, and thus a tad more noise apparent when the black level goes down below the read noise. As a general trend though it's very hard to demonstrate a systematic advantage for larger pixels.