Google TV announces new features to help you tailor your TV experience: profiles, glanceable cards, and Philo as a new live TV provider.
Google TV to Add Watchlists and Personalized Profiles
Make Google TV more you with personalized profiles
Android TV: How To Set Up A Restricted Profile On Your Nexus Player
How to Set Up Google TV User Profiles
Add Google TV Profiles: Here's how
How to set up kids' profiles on a Google TV device
So the new Android TV UI (don't confuse with the Google TV UI) is rolling out profiles support (courtesy of @GenesisDH), I imagine that the old UI won't benefit of this, specially
Google TV Profiles are now available to most users
How to Add a Picture to Your Google Meet Profile
How to Set Up Google TV User Profiles
Google TV Gets the Big Feature You Asked For