I took a 15 second review of this "Design System" and was woefully under-impressed. They are still using far too small of fonts and half serif/sans serif typefaces that are way too Optima-esque.

I just get the same old feeling that MS has no idea what good looks and feels like.

I am sad mostly because there is probably someone in the org saying "We cannot go too far away from what is established here or else how would we be different?!!!?!"

You don't have to be different, you have to be usable.