I'm with the chorus of sceptics calling bull on 10-bit recovery from an 8-bit quantized source. Basically, all this downsampling 8-to-10 bit business will accomplish is reduce any banding / blocking in the image by a factor of 2.
Think about the original logic -- if you record video at 43444x24437 in 1 bit (i.e. each pixel has a value of either zero or one), then the claim is that with sufficient downsampling you'd end up with an image that is 1920x1080 in 10-bits, and everything would be hunky-dory. Do you expect this situation to allow even a modicum of grading? Say the camera records a light source that is a horizontal gradient. The 1-bit image that we get would be basically a bunch of zeroes followed by a bunch of ones (or vice versa). There is absolutely no way you can grade this no matter how much you downsample it (well, maybe if you go down to a width of 2 pixels).
When an analog source is quanitzed some information will be lost, and I don't see what we can do to recover any part of the missing data.
Edit: Small correction in downsampling numbers.