Arguing for not offending others by saying to someone that they seem to lack empathy is gutsy.
Your comment reminds me of someone on a chat channel who had a nagbot that banned the word 'crazy' (amongst others). Why was 'crazy' banned? Because it might offend crazy people. Being one of those, and knowing people like that, absolutely no-one who would be labelled with the moniker 'crazy' would be offended by the word unless it was directed at them. The idea that a schizophrenic friend would be 'deeply hurt' if I said 'the traffic this afternoon was crazy' is utter nonsense. This forbidden word was forbidden by someone who clearly doesn't associate with the kind of people that were being defended.
And so it is when your black American engineer types the word 'slave', suggesting that their self-identity is so wrapped-up with the identity of a person that their grandparents grandparents barely knew, that they would find a non-directed under-the-bonnet technical term deeply hurtful. It's disturbing that you consider these people you're supposedly defending as being so incredibly emotionally fragile.
There was some interesting commentary in this thread about cultural appropriation and whatnot, which seems to me to be beside the point. My intent was only this: if there are other people rightly upset by something, it doesn't matter if you're not, it doesn't even matter if the majority are not, it's still valuable to have empathy for those those that are. That's all.
For instance, I don't expect others to act (i.e. should be forced to change) because something offends me.
Notes:
Don't confuse this question with me arguing that we shouldn't be empathetic.
I'm also not from the U.S. so my approach and offenses are different culturally than your own.