I was raised as a JW from infancy and clearly remember how things were and the many changes between, say, the late 50's and about 2000, when I left.
I know for a fact that they used to announce the reasons for disfellowshipping, ie., "Joe Blow has been disfellowshipped for adultery." But I never heard them announce any further details or anything about specific restrictions or the like.
Probably due to lawsuits for defamation, sometime in the 70's or thereabouts they changed the announcement to "Joe Blow has been disfellowshipped for conduct unbecoming a Christian." Later, they changed it yet again to the current, "Joe Blow is no longer one of Jehovah's Witnesses."
I remember one time when two disfellowshippings announced on the same night. Two young people of the opposite sex. Knowing people would naturally jump to the obvious conclusion, the elder did have the decency to further announce that the two actions were unrelated.
Pretty soon after a DF or DA is announced, they have a local needs talk which pretty much reveals what was going on. Of course, by then most everyone knows anyway because of the inevitable gossip.