MacRumors published a story thst Apple has released the release candidate Version of tvOS 16.3 to registered developers.

Apple Seeds Release Candidate Version of tvOS 16.3 to Developers

Apple today seeded the RC version of an upcoming tvOS 16.3 update to developers for testing purposes, with the update coming a week after the release of the second tvOS 16.3 beta.

Developers can download the tvOS 16.3 beta by downloading a profile onto the Apple TV using Xcode.

  Apple Seeds Release Candidate Version of tvOS 16.3 to Developers