EDIT:
So according to this thread, this is a Google related change and not Nvidia?
In which case, similar to the banner issue from a previous update, you can get a different launcher (see comments for FLauncher) to avoid it
https://www.reddit.com/r/ShieldAndroidTV/comments/181vh4t/ads_at_full_screen/
If you read the article, it doesn’t sound like the ads and update are related. Some users are seeing ads. There is also an update coming soon.
If the ads are a server side change the update won’t do anything?