To avoid confusion, I want to clarify that I'm not saying Letter VII is official Mormon doctrine. Obviously, that's a statement that can only come from the Church.
What I did in that and subsequent posts was evaluate Letter VII based on the criteria set out in mormonnewsroom, which are the criteria given to the media to guide them in understanding what is and what is not official Mormon doctrine. There is no book of official Mormon doctrine, so the question often arises. Aside from the scriptures themselves, and the official proclamations signed by all of the Apostles, it can be difficult to figure out what is and what is not official Mormon doctrine. Hence the guidance in mormonnewsroom.
The key elements in mormonnewsroom are (i) the First Presidency and Quorum of the Twelve counseling together to establish doctrine, and (ii) having it consistently proclaimed in official Church publications.
If I was a journalist, I would think that Letter VII fits the criteria because Letter VII was consistently proclaimed in official Church publications multiple times and because it was written by the spokesman for the Church who was also the Assistant President (Oliver Cowdery) with the assistance of the President (Joseph Smith) and the approval of at least Sidney Rigdon (First Counselor). That makes 3 out of the 4 members of the First Presidency at the time. The 4th, Frederick G. Williams (Second Counselor), began the transcription of the letters into Joseph's History, 1834-1836, so it seems fair to assume he also approved of the letters.
So far as I know, there is no specific evidence that Joseph and Oliver did or did not counsel together with the Twelve on the topic of Cumorah before publishing Letter VII. But the Quorum of the Twelve was new; they had been ordained by Oliver Cowdery in February 1835, and Letter VII was published in July 1835.
The Twelve at that time could not have provided factual input anyway because none of the Twelve, so far as we know, was present on the occasions when Joseph and Oliver entered Mormon's depository in the Hill Cumorah. This experience is presumably the reason why Oliver wrote it was a fact that the hill in New York is the same hill as the one Mormon describes in Mormon 6:6. He wrote from personal experience.
Plus, there is evidence that at least Oliver (First Presidency) and Brigham Young (Quorum of the Twelve) counseled together about the topic. When Brigham Young taught about Mormon's depository in the Hill Cumorah, he explained that Oliver "did not take the liberty of telling such things in meeting." This means he could only have learned about it from Oliver in some kind of private setting, such as a council. Heber C. Kimball, another of the original Twelve, also related details about the depository. William Smith, Parley P. Pratt, and Orson Pratt, all original members of the Twelve, each published Letter VII, which indicates agreement with it. We could question whether this approval was given between February and July 1835 or afterward, but the mormonnewsroom criteria does not preclude counseling together after doctrine has been established.
No members of the original Twelve, so far as I know, rejected or even questioned Letter VII. (Actually, I know of no modern prophets or apostles who have rejected or questioned the New York location of Cumorah.)
But as I said, this is merely an application of the guidance from mormonnewsroom, not a claim that Letter VII is official Mormon doctrine.
The other obvious question is whether Letter VII qualifies as doctrine even if the First Presidency and Quorum of the Twelve counseled together about it and consistently proclaimed it in official Church publications.
Mormon Newsroom goes on to explain this:
Some doctrines are more important than others and might be considered core doctrines. For example, the precise location of the Garden of Eden is far less important than doctrine about Jesus Christ and His atoning sacrifice. The mistake that public commentators often make is taking an obscure teaching that is peripheral to the Church’s purpose and placing it at the very center. This is especially common among reporters or researchers who rely on how other Christians interpret Latter-day Saint doctrine.
No one is elevating the New York setting of Cumorah to a core doctrine. I think we can all agree that the location of Cumorah is more akin to the location of the Garden of Eden than it is to the atonement.
But that doesn't mean the location of Cumorah is unimportant or irrelevant.
The location of Garden of Eden is irrelevant to the Restoration. (Note: Eden is not Adam-ondi-Ahman, which is mentioned in the scriptures). Eden could be anywhere and it wouldn't matter.
By contrast, the location of Cumorah remains relevant today for the reasons it was announced in Letter VII; i.e., to refute claims that the Book of Mormon is fiction, to anticipate the future publication of additional Nephite records from the same area, and to identify the promised land and nation of destiny described in the text.
When Oliver wrote Letter VII, critics were claiming that the Book of Mormon was fiction, copied from an unpublished book by Solomon Spalding. Oliver's statement that it was a fact that the final battles took place in the mile-wide valley west of the Hill Cumorah in New York was a rebuttal of the fiction argument. Letter VII was republished multiple times for the same purpose. Subsequent apostles and prophets have cited the New York location of Cumorah in General Conference for over 150 years, not only as evidence of the historicity of the book but also because more records will come forth from that area and as evidence that America is the promised land.
Identifying the location of Eden serves no such purposes.
In addition to the respective relevance of the topics, the location of the Garden of Eden was never declared as a fact by someone with personal knowledge of Eden, the way Oliver identified the location of Cumorah. The source of the Eden teaching is Brigham Young, who said Joseph declared that the Garden of Eden was in Jackson County. But Brigham also said he never went to Jackson County. Joseph never had his scribes copy such a statement into his history. No member of the First Presidency wrote and published an article declaring it was a fact, and Joseph didn't encourage others to republish any such statements about Eden being in Jackson County. Certainly the location of Eden has not been "consistently proclaimed in Official Church publications" as the New York Cumorah has been.
In all these respects, Letter VII's statement of fact about the New York Cumorah is different.
Continuing with the mormonnewsroom criteria, Letter VII is not an obscure teaching; it was published in most official Church publications over 50 years and has been cited and referenced by several prophets and apostles, including in General Conference, for 150 years. Because the New York setting has been used by prophets and apostles to establish the historicity of the Book of Mormon itself, it does not seem peripheral to the Church's purpose.
Really, if not for the objections from intellectuals in the Church, Letter VII would be accomplishing today exactly what it accomplished in the past; i.e., it gives investigators (and members) another reason to read the Book of Mormon, feel the Spirit and come unto Christ. Tying the Book of Mormon to a pin in the map, as Letter VII does, grounds the book in reality.
It takes the book out of the realm of fiction that critics put it in. (I criticize the BYU "abstract" map that portrays the Book of Mormon in a fantasy land because I think it conveys the same message as the Spalding theory does; i.e., that the Book of Mormon is fiction.)
As we saw from the experience in the British Mission, many people (I think most) need a reason to believe the Book of Mormon is true before they can exercise faith enough to read the book and pray about it for themselves. Knowing there is at least one real-world pin in the map--the New York Cumorah--gives people a reason to believe.
The intellectuals object to Letter VII partly because they've convinced themselves, by their own subjective interpretation of the text, that the "New York hill" cannot "qualify" as the Cumorah of Mormon 6:6. They teach that Oliver Cowdery created a false tradition about Cumorah by speculating, that Joseph passively adopted this false tradition, and that subsequent prophets and apostles were also wrong when they repeated this false tradition, even when they spoke in General Conference.
In my view, when you pull on the threads of the arguments of the intellectuals, their theories unravel quickly. I've discussed all of this at length in my blogs for anyone interested, but the easiest way to resolve questions about Cumorah is to believe the prophets, not the intellectuals.