A week after the second beta versions, Apple today released the third test versions of the iOS 11.4.1 (compilation 15G5072a) and tvOS 11.4.1 (15M5071b) for developers.
Such versions do not bring any great news with the exception of the possible implementation of the USB Restricted Mode on iOS, something that we still do not know if it arrives in version 11.4.1 or 12, which will be released until the end of September.
These new tests were excluded macOS High Sierra 10.13.6 it's the watchOS 4.3.2 maybe they will paint soon.
It is natural for Apple to continue working on sub-versions of the current systems, since the new ones (iOS 12, macOS Mojave, watchOS 5 and tvOS 12) will still need a few months of testing before they are ready for the general public.
Update 06/18/2018 s 17:09
Shortly thereafter, Apple now released the macOS High Sierra 10.13.6 beta 3 (17G47b); all three versions will soon be painted in the Apple Beta Software Program.