Re: dream on...
I use SQL every day at work. I don't really care whether the server is running Windows or Linux, just whether I can connect and run the queries I need and tune them.
To the extent that Windows is essentially finished, especially for RDBMS servers, this is the beginning of the end. That SQL is one of the "big dogs" of the database world, and that it exclusively ran on Windows was a big USP for Windows Server. It isn't any more.
You don't need Windows domain servers - AD in the cloud will do. You don't need Windows Server to run a DHCP server, a DNS server, a mail server (Office 365, remember), and now you don't need it for on-premises SQL (you didn't really need it for cloud anyway, did you?)
With the advent of Visual Studio Code for Linux, you quite possibly don't need the development stack I use every day, either.
You can only swim against the tide so long. The day of Microsoft dominance is ending. They are slowly, but surely, going back to being just one among the many, and the demise of Windows Server is simply another nail in that coffin. I suspect Windows desktop to be around a bit longer, but macOS, Chrome OS and desktop Android machines need to start selling in bigger numbers before that finally falls off the perch.