As usual on Tuesdays, Microsoft has released a new build of the Windows 10 SDK Preview. The release was a little later than usual this week, but it's still pretty much what you'd expect, with the build number matching that of last week's Windows 10 build for the Fast ring, which was 19018. It's still ahead of the build released to the Slow ring yesterday, though.
While the SDK is available, there's no changeleog available just yet, because Microsoft hasn't published a blog post yet. Microsoft also hasn't released a new build of the Windows Servers Insider Preview this week, so it's still on build 19008 from a couple of weeks ago.
As always, you'll need Visual Studio 2017 or newer to use the latest preview build of the SDK, and you'll also need to be running Insider builds of Windows 10 for it to work. The preview build of the SDK can be used alongside a stable version in a working enviroment, and you can continue to publish apps to the Microsoft Store, as long as they target a a generally available version of Windows 10.
If you're interested, you can download the latest build of the SDK from the Windows Insider website. There are also corresponding builds of the Assessment and Deployment Kit (ADK), Windows Driver Kit (WDK), and Hardware Lab Kit (HLK).