German censorship laws are both kind of weird and very strict. Thus, the versions of the various Wolfenstein games released in Germany have a lot of changes, starting with of course removing all reference to Nazi imagery. It at times baffling, and at other times highly amusing. So you're right, in the Wolfenstein games you fight various Nazi like guys who are never actually depicted specifically as Nazis. You can't say Nazi. You can't even depict Nazis in a clearly unfavorable light, cast unambiguously as evil people getting slaughtered left, right, and center. There are no Nazis in Germany. There were never any Nazis in Germany...

All the swastikas and SS logos are replaced with other emblems like eagles or black triangles or similar. Blood is reduced or removed. IIRC in the original Wolf3D the dogs were replaced with giant rats. And, most hilarious of all, the portraits of Hitler on the walls in the first are still clearly Hitler, but his mustache has been removed so now he's just "some guy." Same with his in game sprite. This change made it to the SNES version, too. His organization gets some generic name like "The Order," or "The Wolves," or whatever. Notwithstanding that the original game was just outright banned in Germany for like 30 years.

Violence against humans is frowned upon or outright prohibited depending on the era in question, so enemies may have ham-fisted changes made to make them actually "robots," by either bleeding oil or sparks or something.

For a deep dive into this sort of thing, check out the GermanPeter channel on Youtube which has a series of videos detailing all the censorship and other changes made to the Wolfenstein series, Doom, Quake, Half Life, and a other popular games.

Nope, history wasn't hidden since '68.

It was about the depiction of swastikas, which is not allowed except for film and art. But it needed a little time to get to the understanding that video games are art.

And it took even longer for companies to make use of that freedom instead of playing it safe.