https://www.bleepingcomputer.com/news/microsoft/microsoft-released-the-windows-10-may-2019-update-to-insiders/

Microsoft has made the Windows 10 May 2019 Update available to Windows Insiders in the Slow and Release Preview rings. If you are in one of these release channels, you can perform a Windows Update and download it now.

As previously reported, Microsoft will be releasing the next feature update to Windows Insiders first so that it can be tested in a wider audience. This will allow Microsoft to gain valuable feedback and resolve any incompatible drivers, software, and bugs before it is made publicly available in May.