Auschwitz number of casualties was indeed revised down seve…

Auschwitz number of casualties was indeed revised down several times. Because, for example, Russia used a 4 million figure and even put it on a plaque at the camp. But no historical scholars took that figure seriously and regarded it as Russian anti nazi propaganda. There was immediate response from historians and researchers that this value wasn't realistic. Early researchers were mentioning the currently accepted 1.1 almost immediately. It took some decades of thorough research for the broader historical community to agree that this estimate was most accurate.

The Auschwitz museum officially revised their figure down to 1.1 million in 1990. It took so long for them because they were under soviet control. And the soviets aren't exactly paragons of historical objectivity