So, I've read through most of the patent's embodiments now. I am not sure that this is actually similar to what ML did. I do think it has to do with noise reduction, however it achieves it in a different way. From what I understand, this patent uses two signals of different ADC "precision", in comparison with the source pixel signal, and a set of circuitry to increase ADC speed, increase ADC accuracy, while maintaining a constant load level despite changing voltages.
The "constant load level" is what intrigued me the most. I believe it is a varying load level in Canon's current ADCs that leads to a bulk of their read noise. When load varies in an electrical circuit, it creates oscillations..."noise", a good example of which would be that electrical buzz in a DC circuit. If you can maintain a constant load, your noise level will drop considerably.
So, while this might not be as interesting as a Magic Lantern-style dual ISO read, I think it would still have the same effective result: Less read noise, more dynamic range at low ISO. The use of reference signals at different voltage ramps is simply to provide a secondary source for comparison with the actual pixel clock, and the option to select the more accurate signal...it really doesn't have anything to do with Dual ISO. I suspect that if Canon ever does pursue Dual ISO, the patent would probably refer more directly to such a mechanism...this patent only really directly referred to high and low precision ADC, constant load, and higher ADC accuracy...none of which really seemed to indicate ISO to me.