(On the shield 2019) If you block this domain with your dns ad blocker, the default launcher will only show ads for the YouTube, Google TV, and Google Play Store apps (not individual shows). I find these to be far less annoying as they use muted tones.
androidtvwatsonfe-pa.googleapis.com
If you have already setup your device and currently see ads, you need to reset the android tv home application data to get rid of them. This will temporarily show you the old dashboard, but the new one will load eventually (without ads).
For me it was much simpler to just add it as a line in the field in my router settings than trying to find a launcher that was better while looking decent.
I also like the look of the launcher minus the ads as well, so that might play into it.
I’m not worried about it breaking any features tied to the ads, and I haven’t had any problems in like 2 years I’ve used it.