We continue to receive beta versions and Apple launched a few minutes ago fifth beta version of macOS High Sierra 10.13.6 for developers. The company also released the fifth beta version of iOS 11.4.1 for developers.
In this case it is the typical Version performance improvements, bug fixes, and stability improvements of the versions. For now we do not believe that it will take too long to launch the final version of this version, the previous beta was launched on June 25 and in this case we do not expect too many more betas for a version that is quite stable and that in any case would have other more versions behind until the release of Mojave.
These versions are now fully available to developers. As I always say in these cases, all these beta versions for developers may contain bugs and therefore it is best to stay out of the way and thus avoid possible failures in our Mac, with applications or work tools. So if you are not a developer the advice is that leave the betas to the developers and wait in case the public version of this beta will come out in a few hours.
Apple remains faithful to the tempos and continue to improve and adapt the versions that will remain installed on those Macs that cannot update to macOS Mojave, so it is important to correct and solve all the problems that are detected in the current versions. At the moment this month and August have to pass before Mojave is officially launched, so there's plenty of time to fix bugs and get this macOS High Sierra ready.