The fourth beta of tvOS 9.2.2 has now been seeded to developers, alongside the update of iOS 9.3.3 today. Like all of the other updates, this version only brings minor bug fixes and tweaks. There are no major changes to the OS, since all of those are coming with tvOS 10. The major update to tvOS is currently in beta right now and is expected to come out some time this fall.
Developers can get the latest beta of tvOS by updating in the Settings app. If you have not installed the update yet, you can download the version from the Apple Developer Center.