No because you don't always move goal posts but simply because someone doesn't always do something doesnt by definition mean "never" either. However here you are putting words in my mouth, something else you do (along with taking things out of context.)
I said the punch was "weird", that is different than saying "unique" but even if i had used that word it would not be entirely inaccurate.
The way the punch is applied; elbow down, fist vertical, little body english is what I said, no twisting of the wrist/ elbow as it travels to the target, rotation at the waist, the punch coming "from the heart" along the centerline, relaxing the striking limb immediately on impact. There are other nuances but these are the most obvious. Then you have the idea behind it, "keeping" your weight behind it, unlike others where by leaning into, or the body english already noted above have the practitioner "throwing" their weight behind it.
Also btw I NEVER said "no" shoulder rotation, you need shoulder rotation for a punch to have power. What you don't do is jack back, load, whatever that arm, the way you do with say a strong boxing punch. Part of that of course is due to the elbow position and straight nature of the punch limiting the amout of shoulder movement but I am really trying to figure out how you got specific rotations out of the term "body english."
Other arts have similar punches, but the key word is "similar", which doesn't mean identical. The differences are in all those little details being in the same place. Various arts do share traits with the WC punch but I challenge you to find an art whose punch shares ALL of the traits. If there isn't one then, according the Webster's, that makes it unique, though I prefer the term weird since there are ones that are similar.