They are also, very much, embracing Linux. More and more of Azure has Linux underpinnings and we'll see more integration of Linux in Windows, starting with WSLg.
I mean a lot of the Azure stuff is realising that they could either: continue offering Windows Server only and likely miss out on a lot of potential customers but gain some sales of Windows Server, or start offering Linux in their cloud offering. Ultimately they decided to do the latter, and I'd bet that it's the more profitable option.
I think the writing has been on the wall for a while now - Windows (server or otherwise) is no longer considered the money maker - now it's Office and Azure.
Nadella was literally the top Cloud Computing executive at the company before he was picked for CEO.
Yes, but likely they will then "extend" Linux so if an dev is using WSL to develop a linux project you will need to install MS things on your production enviroment, likely in the NET Core world... I am sure this will happen with the full support the Linux Foundation whom they paid off. It will also come by default in Azure I am sure
After they "extend" with MS open source then start to require just a few closed binaries, that is not a big deal right, for the functionality... see VSCode as an example of this in modern times. This likely will be a paid feature unless you use Azure where it will be free...
I don't really see that as much of a concern. If Microsoft announced plans for world domination tomorrow, all I'd need to change in my workflow is which fork of VS Code I'm using.