You’re (and some of the people in the post) are conflating the colloquial and actual definition of historical revisionism.
Colloquially it just means lying about history, but the real definition is just reinterpriting history in a way that challenged the orthodox view. A great example is the dark ages, which from studying non Latin texts, many authors argue that the lack of knowledge and learning associated with the dark ages is actually just a lack of source texts in Latin from western mainland Europe.
So as you can see the definition of revisionism in an historical context is value neutral, it would depend on who what and how things are being revised.