petra has a point. From what I've read so far, it seems that Morris used the phrase (phrase, note, not just one word) to refer to an issue of great importance (in this case, what happens if there's no Brexit deal) that isn't being openly or sufficiently discussed.
Meaning matters more than mere words.
Also, what if one were to argue that using the n-word in non-personal ways (yes, really! Morris used the phrase about a thing, and a non-physical thing at that, not about a person or people) is a way of trying to defuse its toxicity. Not that I think Morris used it like that, but still... I'm discussing an idea.
Context matters, even if Morris was a bit of an idiot to use the phrase she did use rather than another.
The whole thing looks like a twitch hunt to me.