IT pros will be able to delay Apple updates for 90 days with iOS 11.3, macOS 10.13.4
Apple has added a new variable for device management, allowing supervised iPhones, iPads, and Macs to put off upgrading to a new version of the system software for up to 90 days.
A new "enforcedSoftwareUpdateDelay" configuration profile setting allows a device management administrator to configure how many days an update will be delayed. With the restriction in place, users of the managed devices won't even see the update until the specified number of days has elapsed.
The default for the setting in both iOS 11.3 and macOS High Sierra 10.13.4 is off. Once enabled, it is set for 30 days, and cam be maxed out at 90 days.
It is not clear at present what this means for Apple's signing windows on new iOS releases, if anything at all. It is not likely that the setting will migrate to unmanaged devices, given Apple's stance on OS updates.