It has only been a week since the last round of updates arrived, but Apple unveiled the seventh developer betas for iOS 13, iPadOS 13, tvOS 13, and watchOS 6 today (via 9to5Mac). The update will be available for registered developers who can download it over-the-air on their devices or via Apple's Developer Center on the web. Given the short duration between the two consecutive releases, only minor bug fixes and a bunch of performance improvements should be expected - nothing major. Furthermore, no new updates for macOS 10.15 Catalina have been reported.
Back in June at the WWDC keynote 2019, Apple unveiled iOS 13 showing off system-wide dark mode, updated security features, improvements to the UI, and new versions of Apple Maps and CarPlay, among other things. On the same event, watchOS 6 made its first appearance bringing new apps to the Apple Watch like Noise, Voice Memo, and Calculator. On the other hand, tvOS 13 saw an updated homescreen and control center and iPadOS 13 received updates to Memoji and Share Sheet.
While an official release date has not been confirmed as of yet, Apple has had a history of releasing major software updates around mid-September. That means we might be just a few weeks away from all the bells and whistles of a device running a stable version of the aforementioned operating systems.