Hi,
the reason I said no is because if you accept the Ubuntu system update; it will update to the latest version of ubuntu and not Zorin, you can only do a full OS update of Zorin by installing the next highest version from a disk or USB stick.
This part of the update guide covers this:
"Also note that where it states: "Notify me of a new Ubuntu version" is set to "Never". The reason is because if you allow it to update to any version of Ubuntu, you will most likely lose all your current settings and themes as a complete system update this way leads to the newest version of Ubuntu being installed!!.
You can update an Ubuntu system to the next highest level with the following teminal command, but!; and this is a big but, it will update to a full Ubuntu DE and ruin your Zorin installation:"If you just use the update manager to update; you will be okay, just make sure that in your software sources settings, it is set to "Never" where it states "Notify me of a new Ubuntu version".
Regards Wolfman