Automatic updates not updating
This powershell script is adapted from the VBScript (WUA_Search Download Install.vbs) Microsoft released.
However, unlike the Microsoft equivalent it eliminates the need for user input intervention by providing the ability to pass command line arguments.
If the clients in your organization are capable of and require self-update, but are still not self-updating, see the next section.
If you have the WSUS client installed but the client computer is pointed to a SUS server, Automatic Updates falls into legacy mode and the client computer uses the SUS client user interface.
KB3081448, since it is a cumulative update for Windows 10, simply states that it If you have been following along for a while you know that is the extent of detail we are getting from Microsoft on these cumulative updates.
That certainly points towards the greyed out toggle simply being a bug in the OS versus a new mandatory update policy from Microsoft.
Yesterday Microsoft released three updates for Windows 10 (Build 10240) which included KB3081449, KB3081452 and Cumulative Update #5 (if you are keeping track) KB3081448.
The first two updates listed addressed the Out of the Box Experience (OOBE) for Windows 10 and upgrade compatibility for Windows 10 respectively.
Shortly after the release of Windows 10 Rod wrote about an issue on Windows 10 Home systems that had the automatic app update button in the Windows Store settings greyed out and unavailable.
At the time Rod suspected it was either a feature and just another stage of mandatory updates for Windows 10 Home users or that it could possibly be a bug in the OS.