What is realistic depiction to begin with.
A realistic depiction is showing an army that, yes, was composed of people of varying levels of fanaticism and belief in the Nazi party that nonetheless carried out orders which ran contrary to not only the laws of war but of general morality. This wasn't a couple times, it wasn't perpetrated exclusively by SS units, it was a common theme from beginning to end, and even "heroes" like everyone's precious Rommel are complicit for carrying out these orders or tacitly allowing them to proceed in the name of victory at any cost. Note that even Rommel was more than willing to support Hitler until the war started going south.
There are certainly ways to do such a campaign - maybe the ordinary soldier protagonists are asked to raze a village of civilians. Maybe the player is forced to comply with a horrific order (the light version of this was not received well in Company of Heroes 2). Thing is, I don't trust Relic to do anything interesting with a German campaign. It's okay to show the struggles of a common soldier but I personally think that the player should be made to feel uncomfortable to some degree when taking the reins of a murderous and criminal regime.
But Relic will probably whitewash it all as they usually do and focus on "good guy" Rommel while ignoring how far he was up Hitler's ass after the Fall of France. But the Nazis have been romanticized since the end of the war itself (and maybe even during it) so I can hardly blame them, but I can hope for better even while expecting garbage.