This is a rap, Windows 10 1903 is now officially available.
You can get it either using through WindowsUpdate server, Windows Update for Business, Visual Studio subscription (aka MSDN), Software Center (https://www.microsoft.com/en-us/software-download/windows10) and Volume License.
As part of this availability, you also have the Windows Assessment Toolkit (ADK) used for OS deployment and the new security baseline for Windows 10 1903.
- Download the ADK https://go.microsoft.com/fwlink/?linkid=2086042
- The Security Baseline details is available here https://blogs.technet.microsoft.com/secguide/2019/04/24/security-baseline-draft-for-windows-10-v1903-and-windows-server-v1903/
To know more about what’s new in Windows 10 1903 you can go there https://techcommunity.microsoft.com/t5/Windows-IT-Pro-Blog/What-s-new-for-IT-pros-in-Windows-10-version-1903/ba-p/622024