Looks like Windows Server 2019 may again be available via Volume Licensing and MSDN channels. There were sonme changes made and some notes on compatibilities issues so make sure to read up on it.
More Information
https://cloudblogs.microsoft.com/windowsserver/2018/11/13/update-on-windows-server-2019-availability/
Original Article
For those of you who do not know, Windows Server 2019 went RTM/GA and then it disappeared. There were reports of data loss and problems.. Either way, it’s not available. This means if you want to install Exchange Server 2019 RTM on Windows Server 2019 RTM, you will have to wait. Don’t try to install Exchange 2019 on a pre RTM version of Windows 2019, or you will get this error:
So for now, Exchange Server 2019 RTM is a product without a server to install on.
