A week after the release of the first beta releases, Apple today released the second builds of macOS Mojave 10.14.3 (18D32a) and the tvOS 12.1.2 (16K5532a). WatchOS 5.1.3 has been left out for now.
Over the iOS 12.1.3 (build 16D5032a), it's worth an explanation. Apple has already released the final version of version 12.1.2 for all iPhones users because of a problem related to a legal dispute with Qualcomm in China not to stop selling iPhones in the country, Apple had to change the software of the iPhone. smartphone to avoid a chip maker patent infringement, so iOS 12.1.2 was released “urgently”. The tests of the old iOS 12.1.2 continue, now under version 12.1.3 (but not to be confused, Apple even called beta 2).
As we talked about last week, these updates will most likely only serve general improvements and bug fixes in the first betas, no relevant news has been discovered, but if we discover anything in these new ones, we'll let you know.
It is very likely that these new versions of operating systems will only be released to the general public in 2019, as we are still just starting testing.
Update 12/19/2018 7:12 PM
It took a while, but the second test version of the watchOS 5.1.3 (build 16S5531a) is also now available to developers.
Soon, all new systems except the clock OS should paint in the Apple Beta Software Program.