Developer kits come with the module flashed to run with that carrier board. You can’t just unplug a module from one carrier board and put it in the other carrier board and have it 100% functional (I doubt any harm would come to the module, but pieces of it might not function, e.g., certain ports or features might appear broken until the new BSP is added). Basically you’d need to add some software into the flashing process which is specific to the Orbitty carrier…the manufacturer provides that software in what is known as the Board Support Package (“BSP”). Most of the BSP will be in device tree changes to compensate for how connectors are wired differently.
The rootfs is just another way of saying the main partition Linux runs in and is the actual content you see when browsing around in Linux. If you don’t save a copy of the original module (a clone) as a way of restoring that rootfs during a flash, then you don’t need to worry about it. A fresh flash usually erases the rootfs and places a brand new system in. A clone keeps that system the same, but I was pointing out that you can’t directly use a clone if the rest of the install is also changing.
Just to emphasize, I highly suspect your module is working and only the carrier board failed, but there is no way to be certain. Someone from NVIDIA may know of a test point you can measure a power rail voltage in order to determine if the carrier simply fails to deliver power.