Apple has released the third developer beta of tvOS 9.2.1 for the Apple TV. Interested developers can get it right now from the tvOS Developer Resource Center.

Apple released tvOS 9.2.1 beta 3 to developers

Following the release tvOS 9.2, which added app folders, Siri text field dictation, and more, it's expected that version 9.2.1 would be a fairly minor release, likely containing bug fixes and performance improvements.