I have seen this suggested elsewhere. It might not be technically feasible.
The “For You” tab on new Google TV isn’t pulling data locally. Same for recommendations. Google suggests stuff based on Google search trends and your search history, and what content streaming services want to push.
On the home page, it even recommends things on services you don’t subscribe to, indicated by a lock icon.
If anyone has the new Chromecast, let us know how Plex Android TV app looks.