A few minutes ago, Apple launched the macOS Mojave 1 beta 10.14.3 for developers and it seems that the typical bug fixes and solutions to the bugs detected are added. Apple does not offer much information about these new beta versions released for developers.
Surely in the next few hours the beta version will also be available to users who are enrolled in the public beta program. Undoubtedly the novelties that we can have in these versions focus on improve system stability and few are the new features that are added in functionality or use.
Apple launches this Monday a new version for developers after making the final version of macOS Mojave 10.14.2 available to all users with the arrival of the group calls using the FaceTime app, the new emoji and the corresponding improvements to the stability and security of the system.
Now this new beta version released for developers adds very specific improvements in functionality. The rest of beta versions for developers like iOS 12.1.2 also add few changes to OS functionality, all of them focus on the stability and security of the system. Hopefully the developers can dig a little more into these new versions and see if there are any news to comment, but in principle it seems that there are not too many noteworthy changes.