Except, I don't think RMS intended this as a "joke". I honestly think he was dead serious, but worried that other people would interpret it as a joke and thus be inclined to remove it, hence his "do not remove" comment.
Technical documentation and reference is really not the place for political commentary. It adds nothing and is distracting. Technical documentation should be just that: documentation; not political diatribe. The politics would be better left to a blog post or something of the sorts.
If he was dead serious, he's an idiot. There was never any proposal to ban all usage of the word 'abort' in the sense of 'bring to a premature end because of a problem or fault' or as a noun meaning 'an act of aborting a flight, space mission, or other enterprise'.
Technical documentation and reference is really not the place for political commentary. It adds nothing and is distracting. Technical documentation should be just that: documentation; not political diatribe. The politics would be better left to a blog post or something of the sorts.