Mr. Garcia Martinez did publish those remarks. I don't know that I would use the word "unsafe", but definitely uncomfortable and less meritocratic if people can go around saying things like that with no consequences.
When leaders make that behavior ok, it gives a pass for others to behave that way as well, and creates a terrible work environment.
We can argue about whether "unsafe" is the ideal word choice. But I don't think it changes that Apple has every reason to fire him if their employees don't want to be led by him.