The revisionist claim is that deaths were consistent with horrifically under-supplied work camps, roughly a tenth of the official history. And the population of those work camps were subversive, communist political prisoners, who just happened to have a particular ethnic minority at unusually high concentrations.

The fact that this page exists is reasonable doubt. The torture of basically all defendants at Nuremberg (not to mention the rules and procedures that were invented for that trial) is reasonable doubt. There are just too many reasonable doubts to consider the official history reliable.