Why did I manually have to reboot the Router and Cable Box after an upgrade outage?

During the night, there was a scheduled upgrade. During that time, the router blinked red and the modem online light flashed between red and white. The cable receiver had its normal time display but there was no video or audio. The modem came back online around 7am, but the router light was a steady red and no TV reception. I manually rebooted the router and the TV receiver. Then everything looked and operated normally. I did get a follow-up email saying, "We need to re-schedule. We were unable to complete this phase of the upgrade." I wonder why the upgrade could not be completed? I am in Saratoga County in New York.