It's helpful when people are being assholes to point to a document describing how they're being an asshole and to cut it out
The fact that this behavior, which would violate most CoCs ever written, came from the top tells you everything you need to know.
It’s just a document.
However, in this case, the presence of the code of conduct has made it trivially easy to point out the language as wrong in a way whoever wrote this for Zig cannot refute.
It’s working exactly as it should.
Holding the powerful to the law is unfortunately, a separate issue to whether it's worth it to have written rules/laws in the first place.
A CoC could still be better than no CoC, even if it fails to rein in abuse from the top.