People can't just make up new definitions for words, to make them mean what they want them to mean. And even if you COULD argue that "self-defense" might include things like verbal de-escalation, it is clearly not what was originally intended to be discussed in those, ehm, discussions.
of course we can. we made up new definitions all the time. that's why we have dictionary. it's full of made up definitions. just take the word "bad". when i talk to folks and they use the term bad, i have to ask a few more times to make certain to know which bad are they talking about. for example, someone said "he's so bad!". i would wonder if that is good or bad.
also, you mentioned "originally intended". you were the founder? just wondering if you are, because only the founder would know what it was originally intended for. i remembered reading history, you know how bad history were written, that the original intention of dynamite, that Nobel wanted, was for construction, but we seemed to stray pretty far from that intention.
very strange about human, we just seemed to make up stuffs to suit our needs. we got to stop doing that. you just can't trust them human. now, them alien from Uranus, we can trust them stay on the right route.