No, that is just my knowledge from using YouTube and my experience with ad trafficking. YouTube's ad revenue comes from the videos you see when you watch YouTube videos, not from the ads around the website or in the UI of the mobile app. Do the current mobile apps even have ads in the UI? I don't think they do.
The point I'm trying to make is that YouTube Go offers a significantly different UX that seems to be about making YouTube more accessible on slower connections. Your speculation about ads in the UI is baseless, IMO.