Wikipedians do seem to operate on the assumption that existing content, even if completely made up, is somehow superior to any recent change, as though content gained legitimate merit and factuality simply by being in Wikipedia. There was a concrete example of this in the edit history of the Thoreau case mentioned in the Washington Post article. The hoaxer had made up a reference to make their nonsense stick. When the hoaxer later himself tried to delete the hoax again, another Wikipedian
REVERTED them, saying, "Rv; the information is referenced; if you say it's wrong, prove it." Just because the content had been on Wikipedia for a few months, it was assumed it must be correct. Discussed in more detail
here.