It's not odd. It's unbelievable, all C5 works except one and to wait a software update to see if it fix the problem sounds like fiction. If camera is not working the problem could be software or hardware, if after a repair the camera still don't work, Sony should take the device and check for hardware failure and not just tell to wait a software update. I am not sure what kind of inspection they performed but I'll call Sony support again to ask for clarification.
Note: it may be a "firmware" issue but if that was the case Sony would have been flashing a new firmware rather than telling the customer to wait a software update that may not fix the issue because not all the software update come with firmware update. Usually after a software update what may be update in terms of firmware is the baseband, not the camera.