I don't know if this was changed for the external release, but when Windows 10 was rolled out internally to employees at Microsoft, a significant fraction (but not all) employees weren't notified and had their machines reboot without warning. This happened in the middle of the workday and caused a lot of employees to lose half a day, and that's in the happy case where nothing went wrong with the install.

> I flagged this article on purpose because I don't consider a random Reddit thread to be a legitimate source.

Maybe you also won't consider a random HN thread to be a legitimate source, but if you ask MS employees you're sure to find some who were either hit by this or know someone who was hit by this.