Maybe it's just people they have suspicions of not being in NA for certain reasons that raised red flags, so now they want to force those people to try to contact them to try to catch them out . . . or knowing Club Nintendo it could just be random bad luck that your redemption got glitched and you're in the unlucky position of not being able to contact them.
The one bad thing about the rewards being digital is even if you do get away with redeeming them outside NA for now, if they do eventually discover you're not in NA they can potentially revoke all your digital rewards like they did to the people that took advantage of the Fire Emblem/SMT4 promo twice. At least with the physical rewards they had no way to revoke them once they were sent out, even if it was a large burden to find a way to get them outside of NA.