There is no way to interpret this as anything other than "we will punish native white people if they speak out against their demographic destruction at the hands of their own government".
You can try to explain it as a kneejerk response, or ass covering, or just people following orders, but you cannot deny that this is a direct threat against the british to stay silent about their ethnic bombardment. It is plain as day, and anyone trying to deny it is being intentionally disingenuous because they hate you, they know its a threat, but they're not yet brave enough to say "and thats a good thing" to your face.