That's just an ideological step that is unwise to adopt. Taking that as a philosophy, anything you say is an intolerable statement because of who might get offended by it. This is antithetical to free speech as prior restraint. I don't know why anyone would subscribe to such a viewpoint. Every philosophy has boons and banes, but that doesn't mean the philosophy is absolute nor moral.
"This is antithetical to free speech as prior restraint"
No, it isn't. Free Speech doesn't mean you get to ignore context, and it doesn't mean you don't face consequences for your speech.
That isn't what OP said though. I believe they were commenting that all words are not the same to every group of people and cultural and historical context matters.
Similarly, Trump is mocked as an orangutan. Is that racist against his European heritage (red/orange hair of Irish/Scottish/German)?