It is all really quite simple:
Those whose names are on their list, or have friends whose names are on the list want it kept secret for obvious reasons.
Those who AREN’T on the list don’t want it made public because, then, their ability to blackmail those who ARE on it will quickly fade away.
Yes. Agreed. Their are vast fortunes of money and influence to be realized up to and even after those involved are dead and gone by not divulging their involvement. But.... how is that much different than the operation itself? Pretending the integrity and reputation of the state smells better than the rot they were up to just doesn’t wash in my opinion.