I learned that Elder Hugh Pinnock, General Superintendent of the Sunday School, asked Peggy Fletcher to eliminate the "Sunday School Supplement" in Sunstone. He (and presumably others) felt that title gave some official endorsement. She agreed to change the title but insisted she would leave it in.
At the end of the conversation Elder Pinnock asked Peggy if she had any questions. She replied yes I have two. First, why was Story of the Latter-day Saints not reprinted and second, why was Leonard Arrington removed as Church Historian? Elder Pinnock said he knew the answer to the first question, namely that the Story of the Latter-day Saints contained some errors. Peggy asked him why couldn't the errors be corrected and the volume re-issued, since Jim Allen and Glen Leonard have said many times they would be glad to correct all errors of fact and interpretation for [a] second edition. Moreover, after refusing to publish a second edition of Story of the Latter-day Saints Deseret Book turned around and re-published Essentials in Church History [by Joseph Fielding Smith] which contains at least 100 times as many errors of fact and interpretation, no reply.
With respect to the second question Elder Pinnock said Leonard Arrington is my friend and I am afraid I do not know the answer, but I will find out and let you know. Next day Elder Pinnock called Peggy over to his office and said he had contacted a reliable source (presumably Elder [G. Homer] Durham) and had the answer. Leonard Arrington was removed from Church Historian to preserve his reputation. He had made some errors in judgment and rather than fire him they simply transferred him and his staff to BYU. Peggy asked him what errors in judgment. He said he didn't know, he wasn't informed. My own feeling is that the biggest error in judgment was our decision to write history instead of propaganda. I have also learned recently that our division has been subjected to Church security supervision of which we have known all along, since 1972, that Tom Truitt, who thought he ought to be Church Historian, has been picking out everything we have written or said that might be questionable or controversial and forwarding that on to Elder [Ezra Taft] Benson and/or Elder [Mark E.] Petersen. In addition to that now it appears that there is additional surveillance of our division. What is most disturbing is the apparent feeling on the part of some that we are letting some historical cats out of the bag. What they ought to realize is that the cats have been out of the bag long before we came in, in 1972 and that our efforts have been to try to minimize the historical impact of those unfavorable facts and to put the lid on other facts that can be found by intense study of Archival material that would damage the Church and all its officers. We certainly have refrained from publishing all the things we have learned, i.e., Elder Benson's grandfather Apostle E[zra] T. Benson was at one time threatened with disfellowshipment by President Brigham Young and in fact came within a hair's breadth of being disfellowshipped. This was well along in his apostleship. [[One of Benson's wives had reportedly been involved sexually with one or more other men, but Benson was either unaware, had chosen to believe her denials, or had apparently ignored the allegations. Heber C. Kimball found the situation "disgusting."... ]] This is only one example of it, there are many other facts and interpretations that we have been careful to keep quiet about. I am of course finding many things about Brigham Young that would be better left unsaid and I am trying to be responsible about my assignment to do his biography.
[Confessions of a Mormon historian : the diaries of Leonard J. Arrington, 1971-1997, Gary James Bergera, editor, Signature Books, 2018]