It most likely seemed like a 'cute' way to allow you to turn it back in if you want. 'Lore' wise, you should keep it. 'Lore' wise it is dishonourable to turn it in. 'Lore' wise you would do things dishonourable with the black market. 'Game mechanic' wise, it's just a mechanism to get your seals back if you need it.

I don't think there's any need to read further into it. I also find it extremely unlikely it would have any other value in the future, as can you imagine the MASSIVE backlash that would occur if it did from all the people who did turn it in. SE does not need that kind of grief ^.^;