I believe you are referring to the explanation for the change made 29 Sep on the profile of https://www.wikitree.com/wiki/Haines-3752, who is the son (also named Abraham) of the Abraham Haines you linked to in your question.
What had happened is that, in a merge that was completed 27 Sep, much of the biographical information and sources had been erased on this profile. This information was restored on 29 Sep. Why the erasure was labeled "vandalism" I do not know; it may have been an honest mistake.
And do not forget the 3rd item in our Honor Code:
III. We know mistakes are inevitable. We don't want to be afraid to make them. We assume that mistakes are unintentional when others make them and ask for the same understanding.