Hi there. Most any of the scripts that you found on other threads can be easily modified to just return a Yes/No type result and then take action on that result. What you'll want to do then is package up the script and a LaunchDaemon that runs the script on some kind of schedule, so it will run it periodically on the Mac all by itself and take the necessary action, if needed. Be cautious though to make sure the script is first checking to make sure whatever domain you're trying to join to is available before trying to rejoin, since it will naturally fail if the domain isn't available at that time.

Once you have something working, use whatever management tool you have to push this package install to your Macs. Once the LaunchDaemon is active, it should do what it needs. I'm simplifying this a bit as you can imagine, but you'll get the idea.

One other caution I just thought of. Not sure what you're using for management, but hopefully it allows for a binding config of some sort that won't contain credentials in clear text. Otherwise if using something like dsconfigad in a script, it would need to have service account credentials that have binding privileges right in it. As you can imagine, that's a security risk, so I really wouldn't do that.