The NVR wouldn’t automatically load. It also wouldn’t automatically name the devices.
However, if the NVR is added with the cams under it, then deleting it would also delete all cams on the account, forcing you to re-add them. If the the NVR is then online while you re-add the cams, it would be easy to accidentally re-add it.
It is also possible that it isn’t the NVR that is being deleted when you are deleting.
An easy method would be to delete all devices from the account. Log out and then in from a PC at user.zmodo.com to check to be sure there aren’t any devices still on the account. Then unplug the NVR from power so that it can’t be accidentally added back with the cameras.