MacRumors published a story that Apple has released the release candidate version of tvOS 14.4 to developers and public beta testers.
Apple Seeds Release Candidate Version of tvOS 14.4 to Developers and Public Beta Testers
Apple today seeded the RC version of an upcoming tvOS 14.4 update to developers for testing purposes, with the beta coming a week after release of the second beta. Designed for the fourth and fifth-generation Apple TV models, the tvOS 14.4 developer beta can be downloaded onto the Apple TV via a profile that's installed using Xcode. Apple's tvOS updates are often minor in scale, focusing on under-the-hood bug fixes and improvements rather than major outward-facing changes.
Apple Seeds Release Candidate Version of tvOS 14.4 to Developers and Public Beta Testers
