"I think that, at the level of basic fundamental principles, we may actually be in agreement. I would agree that it's inappropriate for Editor ""A"" to insert a format that Editor ""A""  ‘’knows’’ is non-standard,  and then request a consensus before it's overturned by Editor ""B"" as soon after the posting as is reasonably practicable,” or at least provide some explanation for using this non-standard format. 

We presumably disagree as to whether, in the subject instance, Editor ""A"" knew, or even suspected, the information (the year of death for the author who had just died that week) which Editor ""A"" added to the article, was in a non-standard format. So then, if that were the case as to Editor ""A"", I think then that Editor ""B"" should obtain a consensus before changing (or deleting in its entirety) the information added by Editor ""A"" in a format that Editor ""B,"" acting alone without a consensus, believes in good faith to be a non-standard format. I think that except in the very rare case where there can be no reasonable belief that Editor ""A"" was acting with a good faith belief that he was adding to the article, but rather, he was vandalizing it, should Editor “B” proceed to delete or edit the work of Editor “A” without first obtaining a consensus, or at the very least, to receive a (favorable) response to his request to Editor “A” that there be a change.

I believe that a procedure like this is in compliance with “assuming good faith”, which as you know is a fundamental principle on Wikipedia: It is this assumption that (other) editors' edits and comments are made in good faith. [Wikipedia:Assume good faith] that, I think, is what is missing in the approach taken by Editor “B.” That is, that Editor “B” should have approached the work (the newly added/inserted information) of Editor “A” with the assumption that we are all supposed to be operating under at all times, that Editor “A’s” additions/deletions/revisions/etc. were made in good faith, and that being the assumption, it cannot be appropriate for Editor “B” to single-handedly and without a consensus, delete all (or even part) of Editor’s “A” work. Does that strike you as an outrageous proposition? I mean, presumably Editor “A” and “B” share common flaws of imperfection found in so many humans, and presumably, going into the issue without any knowledge of the other editor, neither editor can presume that he is absolutely correct in every aspect and that anyone who views anything differently than he is a vandal intent on destroying Wikipedia. 

Isn’t it at the outset basically a 50/50 proposition when an editor goes, to delete the newly added information by another editor, that he may be wrong in making that deletion? And if it’s 50/50, shouldn’t he ask for a consensus before deleting the work of another editor, or at a bare minimum contact the other editor and have some reasonable assurance that Editor ""A"" has received his note/email/posting/etc. before deleting Editor “’A’s” work?

I might comment that in our situation, it was not an instance of Editor “A” changing something that was already on the page and then Editor “B,” seeing what was obviously an act of vandalism in the changes by editor “A,” reverting those changes. Not at all. Editor “A” added new information (the year of death for an author who had just died), and Editor “B,” believing that it was presented in a non-standard format to have this information at that particular place, deleted it. Editor “B” believed that this date information belonged, if anywhere, only on a page devoted to the author himself, and nowhere on a page the subject of which was the author’s work, in this instance, a book.

I do in fact disagree with Editor “B” on that point. I find it very useful to see when, during an author’s lifetime, and also in relation to significant world events, an author or artist wrote or published or created a particular piece of work, Articles about the book, or other work, when discussing the writing and publishing, virtually always includes references to when he wrote the book or when he had it published and even references to when other drafts of the book were created (like Herman Melville losing the first finalized version of Moby Dick at sea and having to re-write the entire book years later, or other such interesting facts, like authors commenting that they would have changed many things in a book if they had written it after a particular event in their lives personal to them (e.g., the death of a beloved father, birth of their own child, marriage, good or bad fortunes, etc.) or events in their lives in which we collectively share in some part (the 9/11 attacks, sinking of the Titanic, WWII, War in Vietnam, the shooting of Ronald Regan/Kennedy/Kennedy/King/VJ day, VE day/man walking on the moon/the falling of the Berlin Wall, or the deaths of Roosevelt’s, Churchhill, Elvis, John Lenon,