Microsoft released a new preview version of Windows 10 Software Development Kit (Windows 10 SDK Insider Preview Build 18327), which you can download and install in latest Windows 10 insiders build from the 19H1 branch.
As it is from development branch, you can compile and test your apps to make them ready. You are not allowed to publish apps to store that built with preview SDK.
The latest Windows 10 Insiders Preview build is 18329, whereas the latest SDK preview build is little lower that that with a build number 18327.
If you are a Windows Insider and would like to prepare your applications with targeted SDK bits, you can download the Windows 10 SDK Insider Preview Build 18327 here. Make sure that, you login with the credentials that mapped with your insiders account.
Download the latest version of Windows 10 SDK Insider Preview Build 18327
