The tabs look like they are plastic. If so I would check regularly to see if they are weakening or cracking. I've had two of the plastic brackets break over the years. Admittedly they had been around a while but it would be a shame to lose that retro plate.
After the second failure I put a metal plate behind the bracket and mounted the
license plate to it. That made a much solider attachment.
BTW - This was on a pop-up camper I used to own, not my
EggCamper. The
EggCamper came with a metal bracket for the
license plate. That should be fine until the metal moths get to it.