You know, they are implementing that rule, but I am sure this will have to be published in a watchtower soon.
Here is why: I once told an Elder off; he made a big deal out of something that the WT never wrote about and thus, he was running ahead of the org, being abusive towards me in the process. Then I said I was going to be entertained by what would happen once I complained to the other elders and our CO about it. He stopped pressuring me at once.
Now that this directive isn't formally published anywhere (COs will simply talk about it... its not even in a BOE letter), I would expect some resistance from the great crowd. :)