Apple releases tvOS 11.3 for Apple TV with new filtering options & more
Apple has released the final version of tvOS 11.3 for the Apple TV and Apple TV 4K, bringing several expected improvements -- but not anticipated AirPlay 2 compatibility.

If an Apple TV isn't set to download automatically, the update should be available by going into the Settings app, then selecting System, Software Updates, and finally Update Software, after which an Apple TV should restart and install.
AirPlay 2 is intended to let people stream music from an iPhone or iPad to multiple TVs or speakers, and integrate those outputs into HomeKit. The feature was stripped out of later betas, however, for reasons unknown.
Instead enhancements include rating-based content filtering options in device management, upgraded content matching, and the porting of automatic display mode switching from the Apple TV 4K to 1080p Apple TVs.
The update comes on the same day as iOS 11.3 with the beta of Apple's battery monitoring routines and watchOS 4.3 with the return of music browsing on a connected iPhone.

If an Apple TV isn't set to download automatically, the update should be available by going into the Settings app, then selecting System, Software Updates, and finally Update Software, after which an Apple TV should restart and install.
AirPlay 2 is intended to let people stream music from an iPhone or iPad to multiple TVs or speakers, and integrate those outputs into HomeKit. The feature was stripped out of later betas, however, for reasons unknown.
Instead enhancements include rating-based content filtering options in device management, upgraded content matching, and the porting of automatic display mode switching from the Apple TV 4K to 1080p Apple TVs.
The update comes on the same day as iOS 11.3 with the beta of Apple's battery monitoring routines and watchOS 4.3 with the return of music browsing on a connected iPhone.
Comments
EDIT: Yes it is.
https://www.theverge.com/2017/9/21/16341876/new-apple-tv-4k-review-2017
I see Hulu in my TV section all the time but Netflix is a holdout.
Buggy ass Apple.
That's not an issue by itself, but the list populates gradually after the initial pulldown. The list changes as devices are detected and added. When a new device is added to the list, everything after it moves down one line. That means sometimes the list changes AS I'M CLICKING. I'll move the cursor over "Living Room Apple TV" but the list updates just as I'm clicking, resulting in me accidentally selecting one of the neighbour's Apple TVs.
The access you experienced may be something similarly unintended and innocent.
I still don't understand what this is. I was hoping it was auto match resolution of content to send to my TV for upscaling, but that option does not appear to available after the update. Guess I'm still switching between 1080p and 4K manually then.