Something was stolen - they were giving out copies of Link’s Awakening, not just the enhancements they made but the game and art content of the original game, which is Nintendo’s IP so it is piracy (not to dispute the rest of what you’re saying necessarily though). Projects normally get around this by releasing the fan enhancements as a patch that can be applied to a ROM, shifting the piracy from the project to the end user.
Something was stolen - they were giving out copies of Link’s Awakening, not just the enhancements they made but the game and art content of the original game, which is Nintendo’s IP so it is piracy (not to dispute the rest of what you’re saying necessarily though). Projects normally get around this by releasing the fan enhancements as a patch that can be applied to a ROM, shifting the piracy from the project to the end user.