As well as releasing the new iOS 10.3.3 beta 2, Apple also released a new beta of their desktop OS in the form of macOS 10.12.6 Beta 2.
The macOS 10.12.6 Beta 2 has been released to both developers and also members of Apple’s public beta testing program.
This is the second beta of macOS 10.12.6 the first beta was released a couple of weeks ago and we are expecting the final release some time next month.
Apple is holding their Worldwide Developer Conference next month and we could see the release of macOS 10.12.6 at this event.
Source 9 to 5 Mac