What I am trying to say is that it looks like Nintendo learned from that and didn't repeat it. Nintendo could have actually made an update that looked for the FIRM0/1 protection and removed A9LH. This update would have removed A9LH from an old3DS without hassle, but bricked the new3DS. This update would have also had a risk of bricking clean systems. It seems like Nintendo was aware of this and never pushed out such an update. Nintendo learned from their mistakes and haven't repeated them as of the previous system. So yeah, not really shocking that Nintendo won't want to brick systems again, but I brought up that they didn't repeat it as a means of saying that it's not really the same situation as the brick code.
In an attempt to remove homebrew from the Wii, Nintendo pushed out the update 4.2 for the Wii. This update made changes to the boot2 and resulted in several wiis (hacked and clean) being bricked as a result. Basically Nintendo updated files that they shouldn't have updated in such a manor and it resulted in bricks.