Just another piece of evidence - as if any more was needed - that MS knows where the future is. That future does not include Windows.
Everything else on the planet is already Unix-based. MacOS. iPhones. iPads. Android. Linux servers are already running everything. All phones are running Unix. You can run Linux and Android apps on Windows today. Unix runs on everything from mainframes to watches.
Windows 15 (or whatever) is going to be based on Linux, using the above distro. Count on it. When we see Office For Linux, we will know that Windows is officially done.