In the Canon EOS 5D Mark IV review, I mentioned:
"What Canon has not talked about is the potential for increased dynamic range being available from Dual Pixel RAW files. It seems that, if partial exposures are being captured by the Dual Pixel RAW system, the potential exists for very significant highlight recovery beyond what is already available."
Did you notice that the Canon EOS C300 Mark III Cinema Camera "... features a new Dual Gain Output (DGO) sensor ..."? In the press release, Canon goes on to explain the Dual Pixel CMOS sensor:
"The newly developed 4K Super 35mm DGO imaging system captures high dynamic range content by reading out each pixel through two separate gains. One gain prioritizes saturation in highlight areas while the other suppresses noise in the shadows. The result is an image with up to 16+ stops of dynamic range, clean rich shadows and vibrant highlights in up to 4K/60p."
At 11:46 in Canon's virtual press conference, Paul Hawxhurst, senior professional market specialist, talks about the Dual Gain Output imaging sensor:
"... that expands the dynamic range to over 16 stops. How does it do that? Each pixel on the sensor is split into two different diodes. Those diodes are always taking two frames of the exact same image. Now for Dual Pixel autofocus, it's using those two frames for phase detection. However, the Canon engineers realized that they can use those two different frames and value them at different gains in order to expand the dynamic range. And so what is happening here is that off of diode A you have one image that is low gain and low noise. Off of diode B you're getting a frame that is of higher gain, but it satisfies the pixel's need for saturation. So, these two separate frames that are of the same image of the exact same point in time but at two separate gains are combined and then dumped out of the sensor. Because these frames are of the exact same point in time and of the exact same image, there is absolutely zero temporal artifacting happening in this. What the Dual Gain Output sensor gives is a lower noise floor and hence a much wider usable latitude. Now, this is especially true in the shadow region."
Again, that the Canon EOS R5 will have a Canon Dual Gain Output (DGO) Sensor is pure speculation, but it certainly seems viable – and desirable.