Does running ambian-upgrade do the exact same thing as running apt update and apt upgrade?

You can check this way:

type armbian-upgrade
armbian-upgrade is /usr/bin/armbian-upgrade

 

cat /usr/bin/armbian-upgrade
 

#!/bin/bash
trap "exit" INT TERM
[[ $EUID != 0 ]] && exec sudo "$0" "$@"
apt update
apt -y upgrade
apt clean
apt -y autoremove
exit 0

 

I usually make a quick backup before running bigger updates, especially on systems that are already working well. It also helps to reboot after the update and check armbianmonitor -u if anything seems off afterward. That can provide useful information if you need to troubleshoot.