After looking around on the fire_emblem tag, I've noticed that the nintendo tag has been sprinkled around inconsistently. The vast majority of fire_emblem posts don't have this tag, but pertaining to fire_emblem-only posts (no other copyrights), the nintendo tag exists mostly among the two newest installments in the series.
This could also be extended to other Nintendo copyrights that have most of their posts without the tag, like animal_crossing and metroid.
The reason I ask this is because I see many fire emblem posts that were uploaded without the nintendo tag have the tag added later on by some users. I also feel like Danbooru should have an official stance on tagging the copyright vs. the video game company. I personally didn't think it was necessary to do so, since I always felt that Fire Emblem established its own presence without the overall Nintendo umbrella, with the exception of the Super Smash Bros. series.