People make hyperbolic comparisons because the previous hyperbolic comparisons keep coming true. A decade or two ago, "activists want us to examine all black-colored things to make sure they're not racist" was a ridiculous hyperbolic claim.
And crucially, I'm not irrationally upset over the mere suggestion that we should rethink certain language, and someone withdrawing from a conference doesn't immediately make me think of a fictional evil regime that tortures people for reading a book or saying the wrong thing.
Calling it "rethink" is a euphemism that damages the truth. It is rethinking in the same sense that a true king doesn't have to say he is king as power, deeds, and masses of followers make it abundantly obvious. In this case it is clearly a demand. Actual thinking would involve enough introspection to ask "isn't avoiding black in phrases like the plague in itself suggesting that black is bad far more than any tangental occurance?".
A proper rethinking would be demonstrative instead of imperative - for the previous only demonstrates what they shouldn't do instead of demonstrating what they should do. Coin a new set of phrases for the roles and explain why they are preferrable to the faded zeitgeist. But that would require creation instead of more destructive social bullshit slinging.