This post is way off topic for this blog. I actually wanted to leave it as a comment on the Deseret News website but the comments section went glitchy on me and I finally gave up and figured I would post here and leave it at that.
I was told of an article a few days ago in the Deseret News entitled “Survey clarifies Mormons’ beliefs about race” written by BYU professor Quinn Monson and two other associates. The article concerned me as the authors consistently applied the “folk doctrine” label related to blacks and pre-mortal existence seemingly based on their opinion poll results. I (hopefully) assume Monson et al. specifically mean the exact issue of what occurred in the pre-mortal existence leading to the temporary withholding of the priesthood from black is unknown. That is true. However, the article never really clearly defines that. It seems to more broadly state that the entire idea that something occurred in pre-mortal existence is false (or “folk”) doctrine. If that is their aim (and not just a poorly stated definition), then they are engaging in sophistry, or much worse – revisionist history.
It is simply a fact that some issue(s) in pre-mortal existence influenced the policy related to blacks and the priesthood. A quick look at LDS history reveals two statements from two separate First Presidencies (besides other statements from leadership). The first is a First Presidency letter from August 17, 1949:
The attitude of the Church with reference to Negroes remains as it has always stood. It is not a matter of the declaration of a policy but of direct commandment from the Lord, on which is founded the doctrine of the Church from the days of its organization, to the effect that Negroes may become members of the Church but that they are not entitled to the priesthood at the present time…
The position of the Church regarding the Negro may be understood when another doctrine of the Church is kept in mind, namely, that the conduct of spirits in the premortal existence has some determining effect upon the conditions and circumstances under which these spirits take on mortality and that while the details of this principle have not been made known, the mortality is a privilege that is given to those who maintain their first estate; and that the worth of the privilege is so great that spirits are willing to come to earth and take on bodies no matter what…
Twenty years later, is the letter from the First Presidency of December 15, 1969:
Our living prophet, President David O. McKay, has said, “The seeming discrimination by the Church toward the Negro is not something which originated with man; but goes back into the beginning with God….
“Revelation assures us that this plan antedates man’s mortal existence, extending back to man’s pre-existent state.”
Now, before the anit-LDS folks latch on to this – read the statements. You’ll notice that these and other statements made by church leadership throughout its history have consistently stated blacks would eventually be given the priesthood at the Lord’s due time (that pledge was fulfilled in 1978).
If intentionally written to mislead, Mr. Monson seems to be polling for history. You don’t get history by consensus or declare something didn’t happen or exist (declaring it folklore or “folk doctrine”) because a poll shows most people don’t know about it. History is history – a fact, not a majority rule. It may be politically incorrect but it is doctrine which included a promise fulfilled in 1978. I think it serves us far better to be open and honest than to pretend or imply this didn’t exist (deceptive). Let’s not go down the revisionist history path.
Utah Rattler 
The church recently addressed this issue after a BYU professor’s teachings on race and the priesthood were reported in the Washington Post:
http://www.mormonnewsroom.org/article/racial-remarks-in-washington-post-article
“For a time in the Church there was a restriction on the priesthood for male members of African descent. It is not known precisely why, how, or when this restriction began in the Church but what is clear is that it ended decades ago. Some have attempted to explain the reason for this restriction but these attempts should be viewed as speculation and opinion, not doctrine. The Church is not bound by speculation or opinions given with limited understanding.”
This reads to me like a refutation of some of what you are writing here.
You said, “It is simply a fact that some issue(s) in pre-mortal existence influenced the policy related to blacks and the priesthood.”
This doesn’t seem to be supported by any church teachings after the 1978 revelation revoking previous restrictions on the priesthood for church members of African descent.
Church leaders before 1978 spoke with “limited understanding” before the 1978 revelation and some prominent leaders (McConkie) admitted as much after the revelation in an effort to get people to move on from the folk doctrines you defend here.
What we do know is that Joseph Smith ordained black men to the priesthood and sometime after he died this practice became against the rules in our church. Your efforts to tie this policy to some supposed events in pre-mortal existence aren’t backed by fact…only opinion and yes…folk doctrines.
A good primer on our church’s current teachings on Race can be found on the church’s website here: http://www.mormonnewsroom.org/article/race-church
The church statement, I believe, was in reaction to Bott giving the specific reason of blacks being “less valiant” in the pre-existence. That specific reason is not discussed by prior First Presidencies and other leaders and is “folk doctrine” and the church can and did reject this specific reason (note it is not in the quoted passages that they also consistently stated that no specific event/reason was known for what the determining factor was in the pre-existence). However, the doctrine that some determination was made in the pre-existence is supported by the linked and quoted letters from the former first presidencies (note that both letters were signed by them and were not conjecture). Both were official church statements and not just from the public affairs office or other branch but from the highest church authorities and both clearly refer to the pre-existence being a factor.
As I noted, the Des News article was not well written as it never specifically stated that, I assume, the folk doctrine they refer to is the “valiance” issue. It seems to refer to pre-existence in general and is, thus, misleading.
Yes, Joseph Smith did ordain black men but then policy changed and was again changed in 1978 but that doesn’t relate to the pre-existence doctrine in the aforementioned official First Presidency statements. I would encourage you to read the statements (as well as other past church leader statements) in full as I think they tie in well to the current statement you linked. The linked blacklds.org site also has a wealth of information and a great historical timeline (under “History”) that is a cool resource.