Seems like a bad idea, as many people won't notice (hell DF didn't seem to mention it and they usually do lots of IQ checks... they also missed out when testing Hyper Shadows on 970 vs 390 though....) but will look at the FPS numbers so you'd just make your stuff look worse. I mean look at the gifs I posted, had to even notice that the character's shadow isn't there unless you watch it a few times. It's very subtle.
Edit: Yep, if you look at when they used Shadows: High for 1440p, both cards are missing the shadows in that scene with the enemy (image with circles posted above) and neither appear to have the character shadow either in the opening sequence.
So looks like they tested NV with shadows: High, or for some reason the shadows were capping at high for NV during their 1080p testing.