Devils advocate here: I can give you a binary of my open source MIT code and never phone you the code. The code is still MIT licensed, and open source. You just have no access to it.
That said, I entirely agree that MS is misrepresenting their openness here, which isn’t in the least surprising.
In their defense, most everyone else does the same thing. They still shouldn't do it, but at least they're not the trendsetter here (though they are contributing to the ongoing problem)
? Do you know what “source” means in open source? Like, what is the source of the binary? It’s the code. That’s the source in open source.