Microsoft Was Betting on Unix

They weren't betting much: they didn't go far to promote it, or make things compatible with it.

I did once see a physical box copy of M$ Xenix, the place I worked at had got one in for a customer, some government thing required it. We didn't install it, they were buying a DOS system from us, but for some reason a copy of Xenix was on the invoice too and it was a big deal and overnight delivery from WA to get it.