NOA says
no. Excuse being that without Region locks their Parental Controls don't work.
Some guy on Something Awful debunked this (Albeit with an Australian 3DS, as those can play European 3DS Games.)
So it seems like the main reason they want to region lock the 3DS is due to their Parental Controls system. How they can't handle games from different regions if the system is unrestricted. The hilarious thing about this is that they already do handle games from different regions.
I tested this out with my Australian bought 3DS (identical to European 3DS systems) and tested with a variety of European and Australian games.
We have different ratings systems, Europe uses PEGI and Australia uses the ACB. A rough equivalence of two ratings systems are (there are exceptions):
PEGI --- ACB
3 --- G
7 --- PG
12 --- M
16 --- MA15
18 --- R18
So I set my 3DS to Australia, and restricted my rating to MA15 (the highest the 3DS allows for some reason). All of the European games worked (even Resident Evil Revelations), except for Shin Megami Tensei Devil Survivor Overclocked. SMTDSO was not released in Australia and therefore has no local rating. Also, Shantae Risky's Revenge didn't work, as that was not rated locally either (the DSiWare shop stores ratings info). All DS games worked.
Next thing I did was set the restriction to G, the lowest. My European Animal Crossing worked, Donkey Kong Country Returns 3D did, as did any other game that was rated G by the ACB. Anything that was rated higher than G, even if it was a European version of the game, didn't work. The same to games that were not rated locally.
I set the system to PG to see how it handled games which were rated differently in regions. My Australian version of Kid Icarus Uprising was rated PG, but it was rated PEGI 12 in Europe. Of course it launched fine when restricted to PG. I set the system to Europe, and PEGI 7. The game didn't work, as it was rated PEGI 12.
So the things I found out:
- Games store information on multiple ratings systems and use that for Parental Controls
- For imported games, it will take the ratings information for your local ratings board if it is available and use that for parental control use (assuming your 3DS is set to your local region).
- If there is no local ratings information, it will block the game on all ratings levels.
- DS games have no restrictions.
- DSiWare games do have restrictions, and if the game has not been rated in your region it will be blocked.
So Nintendo is just blowing smoke or making up excuses that aren't really there. And it makes even less sense seeing that if you would need Parental controls anyway why would you import games at all.