Adults buying it for themselves have gotten it already. Purchases for children will be around Christmas. Any big announcements or trailers will catch the attention of parents and family that don’t follow rumours.
Enthusiast will buy early, but they don’t make up long term console sales and non release game sales.
There wasn’t much loss launching it after Christmas. People weren’t buying WiiUs. The 2ds was designed to use all the extra wiiU controller screens they had.