Sadly, what you say is too true. It's hard to know how often one or the other of these events is the cause of coins disappearing, since I have the same issue with other trackables. My collection has some proxies out in the wild, and there were several more ready to go when I decided that, in order to turn the proxies loose, I would have to activate the coins, which I now prefer NOT to do. The numbers get "borrowed" and show up in lists at events or online.
The coin you have is quite pretty, and sharing the photo when finding the proxy works well.
This one needed some love and the chance to move on in the world.