I'm saying that each photosite definitely is included in more than one output pixel, and I'm also saying that the number of output pixels should be about the sa

I'm saying that each photosite definitely is included in more than one output pixel, and I'm also saying that the number of output pixels should be about the same as the number of photosites. This is obviously capturing less information than if you had a completely separate set of photosites for each pixel, but the megapixel count of cameras is nevertheless accurate. Modern cameras sometimes come with a "pixel shift" function, which uses the image stabilization system to take 4 images each shifted one photosite from the others to construct an image where each pixel contains the information of 4 independent photosites with no sharing between the pixels. The resolution of the final image is the same as a normal image, but the result is much clearer, and far less likely to suffer from blue/red moire.