I cannot speak what happened prior to August 1, 2016 so I won't. According to all indications this is a letter that was sent out to all BOE to be put into their permanent file for policies and letters. It does seem to indicate that it replaces a letter from 2012. Since the guidelines for all service departments make reference to this letter then it would indicate that it is policy for worldwide Jehovah's Witnesses. Unlike the policy for safeguarding children that is a policy exclusively for the country that is listed in the title. There is one for Australia and one for the UK. The policies on safeguarding children in Australia is still being determined how to verify that each witness sees it or gets the information that is contained in it.
And yes there are some states where mandatory reporters laws are little fuzzy at best. But just because there is a policy to report all cases because that profession is a mandatory reporter, doesn't mean that it is not stated in that policy for the reason. Look at the LAUSD policy on child abuse. Note that they explain why there is this policy and that is to comply with the mandatory reporting laws in the state. People on here love to downgrade the legalise or the legal nuances of something but that is how law works. Something can only be reported if it is illegal.
http://achieve.lausd.net/cms/lib08/CA01000043/Centricity/Domain/383/CHILD%20ABUSE%20AND%20NEGLECT%20REPORTING%20BUL-1347-3%20FINAL.pdf
Also note how complex some of these laws are. Lets take a state in Australia
The reporting obligations in the Northern Territory:
A person is a child up until they are 18, but the age of consent in the state is 16. Now if a child is 14 and a medical practitioner can determine can determine, "If assessment of the young person (over 14) clearly identifies that the sexual activity is between developmentally normal peers aged within two years of each other, and is consensual, a report is not required." But just because a teen is 16 or over doesn't mean that all "consensual sex" is legal another part of the code says "An adult who has a special relationship commits an offense if he/she has intercourse or commits and act of gross indecency with a child over 16."
That is why elders are required to get legal advice from a trained lawyer on a case by case basis because the law is complex.