The headline and parts of the article suffer a bit from clickbait by conflating the two different ways “revisionist” is used—sometimes to mean revising past precedent with new knowledge, and other times to mean purposely hiding facts about the past (also called negationist history).
Obviously not all history is purposely hiding facts about the past…
But if you ignore that, the author did a good job of explaining how lots of at-one-point accepted history was originally introduced with revisionist/negationist/biased aims. To the point that it’s harder to cleanly separate out all the negationist history than you might think.
So overall an interesting point and a useful reminder of how these interpretations are always in flux. And that that’s okay and healthy.