Apple has just seeded the second beta of tvOS 11.4 to developers for testing purposes, two weeks after seeding the first beta and three weeks after releasing the tvOS 11.3 update.
tvOS 11.4, paired with iOS 11.4, reintroduces AirPlay 2 features that were present in early tvOS and iOS 11.3 betas but were removed ahead of release. With AirPlay 2, the same audio content can be played on multiple devices (like the Apple TV) throughout your home. After installing iOS 11.4 and tvOS 11.4, the Apple TV will once again be listed in the Home app.
There were no other new features discovered in the first tvOS 11.4 update, and it’s likely it focuses on bug fixes and other small improvements. Apple’s tvOS updates have historically been minor in scale, and we may not find any other new additions.
To update, developers must have the proper configuration profile installed, and the Apple TV set-top box must be connected to a computer so the pre-release software can be setup via Xcode. If the developer already has a registered fourth- or fifth-generation Apple TV, they can also turn on automatic updates, which will pull down the latest beta seed as well.
If Apple does add any new forward-facing features to tvOS 11.4, we will update this post accordingly. There is likely going to be a corresponding public beta released for this software at some point in the near future. Likely sometime this week.