My problem with the Repro argument is that (in most cases) everything can be repro'd. If the database is complete and includes all reproductions for each region, we essentially get several worldwide release database. Sure some games require special chips (NES Sunsoft games). But if you have a programmable IC, you can repro any game.
The only reason I see repros wanting to be listed is to list those acclaimed games that routinely get repro'd. The games like Mother, Golden Axe 3, Monster World 4, etc. The only reason these repro games would be listed on the database as opposed to others is due to popularity at the time.
My feeling is, if I have a repro of Monster World 4, I'm going to list the JP Monster World 4. The repro is the ROM of JP Monster World 4 dumped on another cartridge with a fan translation. I would be hesitant to say the repro cart has any right to be separately listed an an NA region. Does it have a region?
If someone has a repro, let them list it under it's original release. Seriously, it is easy to make your own repros with the right equipment. It is almost literally the same as burning a game.
This is wicked cool, but does not warrant a new spot on the database. Especially if it is just a region issue. Otherwise I want my homemade repro of Super Mario 2 (Japanese Lost levels) added. I burned it to a chip myself. Hell, I even printed out a nice label.