jbishop0511 Most likely the SfB Online Device Updates services will be disabled prior to that event to prevent any incorrect versions being pushed back onto phones which would then break registration on them.
kevinmoran Regardless of whether Microsoft moves the date back or not you shouldn't be running outdated firmware on your phones. Any firmware releases from 5.9.4 and newer (including 6.x) can only connect to Office 365 using the app model so once they are upgraded and the app is approved in the tenant then it's moot when Microsoft removes the legacy method.