MacRumors published a story that Apple has released the second beta of tvOS 14.6 to registered developers.
Apple Seeds Second Beta of tvOS 14.6 to Developers
Apple today seeded the second beta of an upcoming tvOS 14.6 update to developers for testing purposes, with the new beta coming one week after Apple seeded the first beta. Designed for the fourth and fifth-generation Apple TV models, the tvOS 14.5 developer beta can be downloaded onto the Apple TV via a profile that's installed using Xcode.