I am aware of Microsoft's history, and I am fairly certain that Microsoft changed behavior towards the FLOSS community is not out of love for free software.
But Microsoft must have, over time, tried nearly every single dirty trick in their playbook against Linux/FLOSS, and none of that really worked. Short of taking out a hit on Linus Torvalds, there is little they can do to keep people from using Linux (and even that would not really help).
And in the face of this situation, the attitude at Microsoft now seems to be, "if they are going to run Linux on the server, at least we want them to use our cloud to host those servers, and our development tools for building their applications". They may do so only because they have no other choice, but so what? The olden days where Microsoft utterly dominated the IT landscape or developer tools are gone and unlikely to come back. Microsoft wants to stay relevant, so they go with the flow.