Facepalm: Instead of relying on Windows Insiders, employees, and willing participants in testing updates, Microsoft has decided it is acceptable for regular users to receive patches before they are known to be stable if they opt to click the "check for updates" button on their own.
Windows Updates have caused a number of issues this year. Most notably the October 2018 update was responsible for deleting users' files without their knowledge. In a blog post by Michael Fortin, Corporate Vice President for Windows, it is made clear that home users are intentionally being given updates that are not necessarily ready for deployment.
Many power users are familiar with Patch Tuesday. On the second Tuesday of each month, Microsoft pushes out a batch of updates at 10:00 a.m. Pacific time on this day containing security fixes, bug patches, and other non-security fixes. Updates pushed out as part of Patch Tuesday are known as "B" release since it happens during the second week of the month.
During the third and fourth weeks of the month are where things begin to get murky. Microsoft's "C" and "D" releases are considered previews for commercial customers and power users. No security fixes are a part of these updates, but for good reasoning. Microsoft has come out to directly say that some users are the guinea pigs for everyone else.
"The intent of these releases is to provide visibility into, and enable testing of, the non-security fixes that will be included in the next Update Tuesday release."
In some fairness to Microsoft, C and D updates are typically only applied when a user manually checks for updates by clicking the button buried within Settings. However, if end users really wanted to be a part of testing the latest features, the Windows Insider Program is designed exactly for that purpose. Someone looking for standard updates may just want the latest security patches and nothing more.
There are a number of steps detailed on how Microsoft does go about trying to ensure updates roll out smoothly without any problems, but even after extensive testing, track records indicate that the system still has plenty of room for improvement.