Not in excess of what would be expected for the generation of chip. ADC architecture impacts very deep shadows, not mid-tones. Whether or not a sensor has on/off chip ADCs is invisible until you push shadows more than 2ev. I'm not aware of Canon ever having a problem with noise in normal shadows or mid-tones versus the same generation from other manufacturers.
I'm not actually comparing Canon sensors to other manufacturers. I was comparing old Canon sensors to the best Canon ones in terms of DR (5DIV/EOS R).
As a side note, the noise, as far as I understand, affects the whole tonal range, however the signal becomes stronger in the mid-tones so the noise is less noticeable. But on older Canon cameras you can see this fine noisy grain even in mid-tones. The noise isn't awfully bad but it's there, you can see it. It probably exists in 5DIV images too, but not really perceptible. It can be revealed if you push dehaze and/or clarity to 100.
Shadow recovery on 5DIV is clean, but the shadows from the old sensors (e.g. 5DII) can't be pushed too far, they start producing unacceptable luminosity and colour noise from 2-3 stops. And it's the same 14 bit for many years - but ADC becomes less noisy.
Sorry to nitpick, but I hate generalizations like this because they wind up being "Canon sensor bad" and "Sony sensor good." Case in point: in another thread discussing the RP I pointed out that 6D2 (and by extension RP) high ISO is much better than A72 high ISO and not too far off A73 high ISO. I got called out on that because "Canon sensor old" and "Canon sensor bad" and "Canon sensor reused" and "Canon low DR"...until I posted an example. The A7 sensors...all three generations...have a superior ADC architecture. But the 6D2 sensor architecture is superior in other ways to the first two generations.
I never said Canon was bad compared to Sony or bad on its own. What I was saying, I didn't feel RP meets my expectations in terms of DR. I'm ok with 5DIV and I'd expect an improvement in terms of DR from a new prospective R camera. I haven't had 6DII, but I played with its sample raw files and no, I wouldn't like to downgrade from 5DIV even as a secondary camera.