...a person may develop and employ technological means to circumvent a technological measure, or to circumvent protection afforded by a technological measure, in order to enable the identification and analysis under paragraph (1), or for the purpose of enabling interoperability of an independently created computer program with other programs, if such means are necessary to achieve such interoperability, to the extent that doing so does not constitute infringement under this title.
I do not see Nintendo trying to stop Dolphin on just the keys. If they end up losing that battle, it could lead to other emulators just including decryption keys as well.