MacRumors published a story that Apple has released the second beta of tvOS 16.4 to registered developers.
Apple Seeds Second Beta of tvOS 16.4 to Developers
Apple today seeded the second beta of an upcoming tvOS 16.4 update to developers for testing purposes, with the beta coming two weeks after the launch of the first tvOS 16.4 beta.
Apple Seeds Second Beta of tvOS 16.4 to Developers
Registered developers are able to download the tvOS 16.4 update by downloading a profile on the Apple TV using Xcode.