Yes - but possibly not in the way I think you mean. The original RAW image is spatially oversampled (20MP or more) with respect to the final output resolution (8MP). The process of converting the original high-resolution image to the smaller image is downsampling.
The Wikipedia pages are helpful here, and explain this probably better than I can:
These also give an example of how this can be exploited to give more resolution (DR) than the actual converter (sensor pixel).
And that must be why an 8KHz downsampling of a CD has more than double the dynamic range of the original, right? You can google theorems, fine, but apparently have no idea what they mean and where they are applicable. So you must work at DXO, then?
Try a test--take a D800 photo of Stouffer wedges, push exposure in post how much you like, and make a note of the darkest one. Now downsample to 1/64, i.e. ~0.5mpix and repeat. How many extra wedges appeared? Exactly as many as how much the *oversampling theorem* is applicable here--i.e. zero.