MacRumors published a story that Apple has released the third beta of tvOS 15.5 to registered developers.
Apple Seeds Third Beta of tvOS 15.5 to Developers
Apple today seeded the third beta of an upcoming tvOS 15.5 update to developers for testing purposes, with the software coming one week after the release of the second beta.
Apple Seeds Third Beta of tvOS 15.5 to Developers
Developers can download the new tvOS 15.5 beta by downloading a profile onto the Apple TV using Xcode.