How do we know they have given that up? Many still aren't convinced that non-free software is absolutely a good idea (though it hasn't bitten us yet that much).
Just because they are in the "embrace, extend" phase, doesn't mean they isn't an extinguish coming.
Understand though that "extinguish" may have changed over the years. Only time will tell.
Honestly, I have yet to see something come out of MS' open source work that I actually care about! I'm happy in my non-windows world. What have they even done that applies? TypeScript and VS Code? These are essentially irrelevant to me. So what reason do I have to extend my trust to them?