I was discussing this with a good friend of mine his response was this. "The GOVT has given me a way to put on hold vehicles and I can do this online. My interests are not with newish cars so I can remake the stamped chassis plates no hassle. So what do I have? I have 100 odd cars in the system and most have been scrapped but I have the chassis numbers neatly stored in the LTSA computer. If I buy a car and its dereg I copy the plate and give it my existing chassis number in the system." The process is a real cost saver.
If you claim the plates are lost you can get replacements. If you really keen you save the tags on old cars and the plates. Makes a rusty parts car with live redgo worth a bit.