Following up on the first beta of iOS 12.3 earlier today, Apple has now released the first beta of macOS Mojave 10.14.5. This new build is currently available only to registered developers and is build 18F96h for those keeping score at home. At the time of this post, the build has not been released to those registered in the Apple Beta Program. That could happen as soon as later today but likely will be at the end of this week or early next. Apple tends to delay first beta builds to the public beta testers.
The release of the first beta of macOS Mojave 10.14.5 comes just two days after the public release of 10.14.4. As for what is expected in 10.14.5, it is likely going to focus on bug fixes and performance improvements. It is also possible that we will see the macOS version of the Apple TV app. During the Apple event on Monday, the company indicated that the revamped app will be a part of macOS.
If the Apple TV app does make it into 10.14.5, it all-but locks in a May release date to the public. Apple was clear that the new TV app will be available on iOS and macOS in May.