I haven’t seen this myself in the parks, but it does happen on the cruise line. I would guess it’s very difficult to sell pins that were part of a particular event that has passed. So, Disney sometimes put those pins on CM lanyards. For example, on the Disney Wonder, you can sometimes find pins from the cruises to Alaska in the fall and winter after the summer season. So, perhaps there were leftover pins from the marathon that didn’t sell, and so this is how Disney is choosing to get rid of them.