I hesitate to jump in here, especially with a response that isn't explicitly an answer to the question, but there seem to be misconceptions that need to be addressed.
To start, I believe it's important that we try, when addressing issues about genetic genealogy, to draw a distinction--or at least to make specific the perspective from which we're speaking--between WikiTree policies and guidelines about employing the use of DNA for genealogy, and the more general and encompassing world of genetic genealogy practice. These are not the same things.
The concept of autosomal DNA triangulation was adapted about 10 years ago from the term's original use where its application--even if it wasn't explicitly called "triangulation" at the time--first began around 2001 or 2002 with uniparental DNA, the Y chromosome and mitochondrial DNA. Yes, yDNA and mtDNA triangulation have been a thing for quite a while.
Initial use of the term in relation to yDNA has been attributed to genealogist William Hurst, writing in December 2004. However, I believe the credit goes concurrently to Charles Kerchner who added the article "Triangulation Method for Deducing the Ancestral Haplotype in Y-DNA Surname Projects" to his Genetic Genealogy DNA Testing Dictionary about a month earlier. In that 2004 article, Kerchner defines triangulation this way:
"A method of determining the Ancestral Haplotype from the haplotype data of known direct line descendants. In Genetic Genealogy, the process of determining the Y chromosome DNA Ancestral Haplotype of a male ancestor by looking at the allele values of the DYS markers in the haplotypes of the tested individuals in a surname project who descend from that ancestor by focusing specifically on the direct paternal line descendants of two or more known and different sons of the common male ancestor. Unless there is an exact match at all alleles at all DYS markers in the haplotypes of the two different direct male lines of descendants, at least three haplotypes are required to triangulate and deduce the ancestral allele for each marker."
There has never been any restriction or limitation--and I'm speaking generally, not about WikiTree guidelines--in the number of test takers used in a triangulation, whether for yDNA, mtDNA, or autosomal DNA. In that sense I believe "triangulation" was an unfortunate choice: it's tripartite implication is that you're always done when you get to three; Jim Bartlett, for example, has written that he has on the order of an average of 25 test takers in each of his autosomal triangulation groups. There also has never been any restriction or limitation that sets a demarcation saying you don't use autosomal triangulation for relationships of 3rd cousin or closer. That's WikiTree policy; understandably, they had to draw a line somewhere and 3rd cousins will share a meaningful amount of atDNA 92% of the time. Further, there still, to this day, is no scientifically studied, peer-reviewed research that indicates one way or the other that autosomal triangulation among distant cousins is even a valid and accurate procedure.
Triangulation, in all its permutations, is simply an analysis method, not an end product. At its core it's merely a way to group together DNA test takers who likely share a common ancestor, a vectoring method as a tool to determine a correct course or bearing. Think of bygone ocean navigation using the positions of the stars.
We FTDNA surname project administrators have been doing it since at least 2002. We can't separate members of a yDNA project into groups without analyzing their STR values and arriving at a determination of who align closely, who have few enough collective genetic distances so that a modal haplotype can be defined...or at least hypothesized. Even phylogenetic network mapping for yDNA like Fluxus and SAPP wouldn't exist if we didn't practice triangulation with multiple test takers. Those phylogenetic tools can't be used for only two test takers, and their accuracy increases with both the depth of the testing employed and the number of test takers.
My personal belief is that there are multiple elements in the WikiTree "Confirmed with DNA" guidelines that have been established independently and unilaterally by WikiTree, and that some of those elements are insufficient or even incorrect. But that's where the importance of the distinction comes into play: WikiTree is a one-world family tree; it is not a genetics or DNA testing service. It has to walk a very fine line between purpose of use and accuracy, between ease of application and the very complicated and ever-changing depths of our understanding of genetics. Keep in mind, shocking as it may be to some, that it's been less than a year since we, for the first time, successfully sequenced an entire human genome. Our inexpensive microarray tests can't look at almost 8% of our autosomes (and the tests return results for only about 0.2% of our genomes), and even the Big Y-700 test from FTDNA can attempt to examine only 41% of the Y chromosome.
I believe WikiTree provides us with an excellent platform for incorporating some generalities about DNA into our genealogies: good ways to show genetic relationships among ourselves and our ancestors, and good ways to indicate avenues for additional research. But there are very, very few absolutes in genetics. What we know of the science changes rapidly--just try keeping up with the academic publications about human genetics; that could be a full-time job by itself--and most if not all of its application to genealogy is driven by math, by probabilities and statistical theory using somewhat arcane methods like Bayesian inference, Poisson distribution, the Burrows-Wheeler transform, and hidden Markov models.
What genetic genealogists should do is learn as much as they can and bring with them every tool in their toolbox, along with a hefty dose of the scientific method and objective skepticism. The three types of tested DNA--autosomal DNA (including the X chromosome), yDNA, and mtDNA--should never be considered as disparate, standalone silos that have no connection. All of it is in our DNA. Fourth cousins will share meaningful autosomal DNA only about 48% of the time. The odds that 4th cousins along the patrilineal line show almost exact yDNA signatures is very nearly 100%. Mitochondrial DNA is quirkier and more unreliable (for instance, see Blaine Bettinger's discovery that his mtDNA didn't match his mother's...and happy birthday, Blaine!), but affirming autosomal matching with closer matrilineal cousins provides an opportunity for more accurate use of mtDNA on the family tree.
Against that backdrop, I understand Richard's request. What he describes is a common and valid yDNA triangulation. That's precisely where you start in building out a "yDNA family tree" like the one for our little Williams subproject. You figure out with whom, when, and where the yDNA data diverges, and that allows you to determine the distinct branches of a patrilineal line. Whether or not a modification or addition to the WikiTree "Confirmed with DNA" guidelines is made--or in fact whether someone chooses to use the "Confirmed with DNA" status--I feel that the confirmation citation format is only that: a citation. Genetic evidence is never as simple as citing a census record or a birth certificate. I think--per the genealogical proof standard--that at least one of the profiles involved, typically the MRCA keystone, should contain detail in the Research Notes section that sufficiently describes all the tests taken, the information evaluated, the evidence analysis process and reconciliation of any data disagreements, and then provides a cogent explanation of the conclusions.
