While I'm aware of letters to BOEs covering the confidentiality of child abuse cases, I've never seen a copy of any letter stating any kind of "punishment" other that the standard ones that relates to "an Elder that breaks judicial confidentiality may no-longer qualify as such". And as such a "punishment" letter would have to had been sent to every congregation Body world wide to be effective, I'm a little surprised that not one copy of it, has surfaced publicly when we consider how many ex-Elders and sympathizers are anti child abuse supporters.
I may be wrong ... but I'm fairly sure that if Elders were threatened with disfellowshiping for reveling child abuse the police (as I understand what some are saying here), that letter would have surfaced in the Australian Royal Commission and been used to rip apart the Watchtower defense.