I guess they really were full of shit.

Microsoft has been discussing the idea of Windows as a service, but the company hasn't really explained exactly how that will play out with future versions of Windows. That might be because there won't really be any future major versions of Windows in the foreseeable future. Microsoft has altered the way it engineers and delivers Windows, and the initial result is Windows 10. Instead of big releases, there will be regular improvements and updates. Part of this is achieved by splitting up operating system components like the Start Menu and built-in apps to be separate parts that can be updated independently to the entire Windows core operating system. It's a big undertaking, but it's something Microsoft has been actively working on for Windows 10 to ensure it spans across multiple device types.

https://www.theverge.com/2015/5/7/8568473/windows-10-last-version-of-windows