Windows 10 had its sunset date announced back when it launched. Most versions of Windows have only come with a two year support life cycle. The LTSC lifecycle has been halved recently, but the 2019 LTSC release will still get 10 years of support like before.

Windows has, before Windows 10, had a support cycle of 5 years for feature updates and another 5 for maintenance. XP was supported past that term for (too) long because people refused to or were unable to switch, and 7 has befallen a similar faith.

The news media recently found the support cycle page again after the leaks about the upcoming Windows 11 release, but none of this should be a surprise for people who need to look into long term support for Windows.

The difference here, or course, is that a big company like Microsoft is more likely to stick around than a small, open source project. They currently don't have any plans to stop support, but who knows what the future may bring. Covid is a stark reminder of how the world can change in just a few months.