heh; i'm thinking of embrace in the same way that MS have embraced Linux (which hopefully isn't a run-up to the other two Es ;P)

This is the "new" Microsoft. Just like the old Microsoft. The other two Es will follow just as soon as the optics permit.

eta: (Sorry to sound old and curmudgeonly, but... I am old and curmudgeonly. I do not believe for one little instant that any corporate culture is capable of reversing its lifelong ingrained habits and postures.)

Indeed. But Matrix seems in a much more dangerous place in that regard then Linux.

That being said, if MS does in good faith embrace Matrix for Teams, that would be amazing.