The editorial was certainly tone deaf and the editor resigned over it. That already strikes me as an overreaction, but whatever; he did what he felt was appropriate. Folks should accept that and move on. The requirement for the entire organisation to fall on their swords and acquiesce to "demands" just seems over the top.

This quote is particularly troubling:  “Further, Canada is ‘exhaustingly white and middle class’ not because white writers are afraid to write stories they don’t ‘know,’ but because white writers don’t get out of the way and make space for the multitude of stories to be told by those who aren’t white and middle class.”

Why should white middle class writers "get out of the way"? What sort of attitude is that? There is space enough for writers of all backgrounds. Even white ones. Telling other people to be silent is an awful strategy for a fruitful, respectful dialogue.