The term Historiography is the term to discuss the “history behind the history”. Usually it’s focused on how the historians came to the conclusions or what their reasoning was.

For me two big topics from WW2 that is still prevalent in the world and are still cited as fact are the “Clean Wehrmacht” myth. And to a lesser extent the Bombing of Dresden.

The Clean Wehrmacht myth is still held by many in history forums and historians to this day. Here is a great explanation on what it is. by u/georgy_k_zhukov But to quickly sum it up it was the idea that the Wehrmacht was innocent of the war crimes committed on the Eastern Front and the war in general. And it was the SS, Einzgruppen, and Hitler that perpetrated the extermination of “lesser races”. But the history behind the myth and how the Allies encouraged it is something that many do not know.

The Bombing of Dresden is more centered on the man who made it famous or infamous: David Irving. I wrote up on this awhile back on who wrote up about the bombing of Dresden. Irving now is only used to cite how he lied about Dresden. No self respecting historian would use Irving as an actual credible source. His later Holocaust denial attitude got him trouble with Austria and he got out on trial. He would admit he made up most of his sources.

Edit: I accidentally linked the same comment for both answers, it’s fixed now

u/TheNorthie already correctly notes that "historiography" is the term that historians use in this context. When going from honours up through my doctorate, understanding how my field evolved was a major learning goal. The thing that tends to evolve is the conclusions we draw from available evidence and the lens we use to view them.

Some interpretations are non-existent among academic historians now. One example is the myth of the "Dark Continent." This was a fallacious view that colonial-era European historians held of Africa that it had no history or change. This is utter nonsense, and a lot of the early academically-trained historians of Africa like Kenneth Dike specifically sought to disprove this idea. Beyond some very colonially-minded individuals, this "fact" is entirely debunked in the academic community. You will still see some amateur historians or non-historians cling to this idea, however.

Sometimes, an interpretation falls in and out of favour, depending on ongoing debates or political contexts. For example, the impact of the industrial revolution on ordinary Britons goes through a flip in consensus roughly every twenty years. The pendulum commonly swings between the industrial revolution having had many positive impacts or being entirely destructive. The vague consensus now is that it depends on the city and decade, and how one defines changes in life. I doubt this question will ever have a uniform consensus because this "fact" is so heavily predicated on how the historian describes quality of life.

There are also some "settled" questions that are largely without debate, but could always change if new evidence emerges. A debate among the Transatlantic Slave Trade that is mostly resolved is the number of enslaved people who enslavers transported across the Atlantic. This debate was fairly active from the 1950s through 1980s, although most historians now agree on the 10-12 million range, depending when you consider the beginning and end. This is because the establishment of the Transatlantic Slave Trade Database contains the overwhelming majority of recorded voyages, including how many people were aboard ships at departures, how many arrived, and which ships were lost to storms or piracy. Unless there is a massive resurgence of previously unidentified evidence, we have enough data to give a solid range. That said, there is still some debate over more precise numbers so the range is what most historians use.

EDIT: Forgot to list some sources

Curtin, Phillip, The Atlantic Slave Trade: A Census, Madison: University of Wisconsin Press, 1969.

Dike, Kenneth, Trade and Politics in the Niger Delta, 1830-1885: An Introduction to the Economic and Political History of Nigeria, Oxford: Clarendon Press, 1956.

Eltis, David, and Richardson, David. Extending the Frontiers: Essays on the New Transatlantic Slave Trade Database. New Haven: Yale University Press, 2008.

Lovejoy, Paul, Transformations in Slavery: A History of Slavery in Africa, Cambridge University Press, 1983.