Hi, @BlxxdyButterfly!
The forum was moved to a different platform at some point because of some issues with the old one so a lot of the features, including the shop, are not compatible and couldn't be transferred to the new platform. I think the shop is still under construction, not all the cards have been uploaded yet as far as I can tell. But either way, once the shop is up and running I'm sure Key will sort out the missing cards. I suppose people who remember what cards they had will get them back.
Also I might be wrong, but I think the cards need to be at least resized to fit the new platform, they look a bit shorter (?) to me so it would certainly take a while for the shop to be up and running. We'll just have to be patient. ^^