You are correct. If oh-my-fish properly included the copyright and permission notice of the MIT license, then they are within the bounds of the license. It does

You are correct. If oh-my-fish properly included the copyright and permission notice of the MIT license, then they are within the bounds of the license. It doesn't matter what the author's requests are, they can use it if they attribute properly. Of course, the author can henceforth change the license for any future code, preventing any unauthorized forks, which would be against then open-source spirit of the MIT license.