The update that is causing the issue will also be blocked from being installed automatically for 30 days, during which time Microsoft will hopefully fix any issues with the update.
Why it matters: Microsoft puts out constant updates for Windows 10, and there's a good chance you've installed some that introduce problems to a system. If Windows detects this, it will try to resolve the failure by uninstalling recently installed updates.
Microsoft has started to release Windows 10 cumulative updates for this month, pushing out a number of bug fixes and improvements. There have been some notably bad updates automatically foisted upon Windows 10 users in recent history, but when bad things happen Windows can often automatically recover, or users can pop into safe mode and dig out the offending software/update.
Back when Windows XP was reaching the end of its life-cycle, Microsoft introduced the "nag" screen which was a popup that informed the user that the OS needed to be updated to Windows 7.
Users can manually reinstall any updates that were uninstalled, but they will be removed again if Windows 10 still doesn't start. The feature will be available to Windows Insiders this week, assuming your devices qualify for it.
Security updates to Internet Explorer, Microsoft Edge, Microsoft Scripting Engine, Windows Shell, Windows App Platform and Frameworks, Windows Input and Composition, Windows Storage and Filesystems, Windows Wireless Networking, Windows Fundamentals, Windows Hyper-V, Windows Server, Windows Linux, Window Kernel, Windows MSXML, and the Microsoft JET Database Engine. I would hope that admins will be able to turn off the notification for endpoints to avoid an influx of support tickets about the upgrades but it's not explicitly clear if this is the case.