tvOS 10.2.2 is only available for the fourth-generation Apple TV. Registered developers can download the update by connecting the Apple TV to a computer with a USB-C cable and installing the beta software using iTunes.
Due to the installation requirements, tvOS betas are only available for developers, so tvOS 10.2.2 will not be publicly available until the finalized version of the software is released.
No major feature changes or bug fixes were discovered in the first two betas of tvOS 10.2.2, and it appears to focus on minor under-the-hood improvements and security enhancements.
tvOS 10.2.2 will be one of the last updates to the tvOS 10 operating system as Apple is already working on the next-generation version of tvOS, tvOS 11.