Still Doom was able to run in 60 FPS on PS4 (best refference, since the PS4 OS is also pretty light). So they could make the Switch 30FPS. Which is a big thing since the power required for 60FPS is pretty big. The PS4 can barely run the Witcher 3 in 30FPS. So expect the visual difference between the Witcher 3 version of Switch and PS4 to be much lager than those of Doom,which where already pretty big. Doesn't mean that it is impossible of course just a huge amount of work.
Isn't that was I said? They could reduce geometry and lighting. My main point is that this method they used to try to debunk it is inherently flawed in concept.