Apple released tvOS 11.2 Developer Beta 5 on Tuesday, along with iOS 11.2 DB5. This tvOS release cycle adds a developer API called AVDisplayManager for automatic display mode switching. It also brings back support for the Unwatched category in Home Sharing.
tvOS 11.2 improves HDR support for Apple TV 4K, but still doesn’t have the Amazon Prime streaming app. Amazon said earlier this year the app was coming soon, but it hasn’t yet materialized.
Developers can provision their Apple TVs for developer betas through the Apple Developer Connection.