According to a support document published at the time, the update was initially supposed to be optional.
System administrators who wanted to remove Flash before the EOL date could access the Microsoft Update Catalog, download the KB4577586 packages, and remove Flash to avoid any security-related issues.
But this week, multiple Windows 10 users reported that Microsoft is now forcibly installing KB4577586 on their devices and removing Flash support from the OS.
While users might think this would cause issues for some enterprises, it actually does not. Last year, Adobe introduced a time bomb in the Flash Player code that prevents the Flash Player app from playing content after January 12.
Even if Flash Player is installed on a Windows device, the OS wouldn't be able to play any content due to this time bomb — a well-known issue that has created problems in countries such as China and South Africa last month.
It appears that Microsoft has also learned of this time bomb and has decided to push KB4577586 to Windows 10 systems this week to remove any Flash code since the app doesn't work anyway.