Well, you wouldn't know what those rares are. If you are Wizards implementing this, you would have the RFID be random digits, and keep a database somewhere to match <string of hexadecimal numbers> with "English STX Professor Onyx".
But it's a good point, the access checks on the database would be a nightmare to handle properly.
Yeah I just mean for your automatic sealed pools concept you need a way for {whoever runs the tournament} to be able to scan a pool, or a verify decklist, which means a 3rd party. Local game stores are not necessarily to be trusted this much - simply because they are in the best position to scan boxes (and in the past LGSs have done shady stuff like this when sets were mappable).
But it's a good point, the access checks on the database would be a nightmare to handle properly.