if each game has its unique ID the key is to find algorithm that Nintendo use to generate them. thinking logicically Nintendo cant provide every software update with complete list of every valid ID that will eat up all available memory just for that kind of database.
Having that kind of algorithm may enable flashcard to generate valid ID each time when 3DS ask for it and N cant do anything about it
I don't know much about how current gen flash cards work but i know that N. has plenty other ways to check for flashcard then stupid game ID...