I remember when Microsoft teamed up with IBM on OS/2, so I'd predict that Microsoft comes out with its own brand of Linux within 5 years. That will give them time to learn what they need to include/exclude and support.
Radio Shack sold Tandy HD machines running Xenix to business customers. In fact, Radio Shack stores themselves used a POS system running Xenix, up until the mid 1990s at least.
Microsoft sold Xenix to SCO in 1987.