When and why is something a Prophetic statement?

There is an interesting article on Spectrum by Alden Thompson entitled Rediscovering Lost Adventist Literature The subject is not really what interests me but rather this information from the article:

Lost-and-Found #1: An Astonishing Ellen White Quote on Conditionality
The astonishing Ellen White quote on conditionality is this one:

The angels of God in their messages to men represent time as very short. Thus it has always been presented to me. It is true that time has continued longer than we expected in the early days of this message. Our Saviour did not appear as soon as we hoped. But has the Word of the Lord failed? Never! It should be remembered that the promises and the threatenings of God are alike conditional.

Her treatment of this quotation is tantalizing. First, it is part of a longer manuscript in which she responds to a critic who quoted this 1851 statement as proving her testimonies false: “I saw that the time for Jesus to be in the most holy place was nearly finished, and that time can last but a very little longer.”⁵

After addressing the question of conditionality at some length (the point of the quoted paragraph), she then refers to her critics in vivid language, declaring that heretofore she had “not felt at liberty even to notice their vile speeches, reproaches, and insinuations.” She goes on to say that she “would not now depart from this custom, were it not that some honest souls may be misled by the enemies of the truth who are so exultantly declaring me a deceiver. In the hope of helping the minds of the honest, I make the statements that I do.”
But she apparently had second thoughts, for there is no evidence in the White Estate files that this response (Ms 4, 1883) was ever sent to anyone and the critic is not identified. The manuscript was found in the Ellen White files after her death. Apparently she never used any part of it while she was still alive. A number of such manuscripts were brought to light in the1930s and then step-by-step brought to the attention of the church. In this instance, part of the statement was published in Evangelism in1946. In1958, it was published in full in Selected Messages, Bk. 1, 59-73.

Now I have used the phrase “astonishing” to refer to this quotation because of the reaction of a retired pastor with whom I have had extensive email correspondence in recent years.  He is devout and thoughtful, conservative, but open to new perspectives. I had used the quote several times in dialogue with him, and more than once he read through the SDABC article, “The Role of Israel in Old Testament Prophecy,” described here as lost-and-found item #2.⁶ “I had read it before, but enjoyed it again,” he said. I finally told him that I would answer no more of his questions until he gave me a straightforward answer to my question about Zechariah 14:

I know this is a volatile question, but if Scripture includes an end-time scenario which no SDA would now affirm, shouldn’t we conclude that specific end time plans, including the specifics in the book The Great Controversy, may not happen exactly that way? I have pressed you on that point because if that conclusion is wrong, I would like to know why. If it is correct, shouldn’t we take steps to educate the church – including those ancient preachers who would rather not come to that conclusion?...

I have to admit I did not know that she never published or even sent out her statement "It should be remembered that the promises and the threatening of God are alike conditional." I have to give her more credit then her followers because if that statement were true then the promise of a second coming becomes no longer a surety but a conditional promise. It may or may not even happen because when phrased the way the quote is "are alike conditional" there is an implied "all" in the statement. It probably would have assured her position as a false prophet. Particularly in light of the context which was to try and explain why her own predictions did not come to pass. Because if a so called prophet is allowed to explain away why their predictions failed then there would no longer be any objective test of prophetic ability. They simply say that the conditions were not met. Which is way to easy if you say that everything is conditional and what those conditions are is never given. (in his article Thompson mentions the Jonah parable, don't put a whole lot of wait on that since it is highly unlikely that Jonah only said those eight words to the people of Nineveh, it is a greatly misused book by those trying to defend Ellen White and condition-less conditional prophecy).

Which leads to the second area of concern which is why her followers and supporters use the quote that she herself did not publish or send out. What gives it any authority or truth to be used at all if the prophet in question did not feel it to be a worthy piece of instruction for people? That strikes me as the assumption that everything someone believed to be a prophet said has to be inspired. Something which in fact even the supporters of EGW say is not true. It does appear to me to be something that should have in fact never even have been published at least not until there is a change in the understanding about how to view her writings and the removal of her writings as "a continuing and authoritative source of truth which provide for the church comfort, guidance, instruction, and correction." (Fundamental SDA belief 18)