Von Braun and the rocket scientists were the most famous part, but not all 1,600 were involved in aerospace specifically.

Here are some relevant snippets from the Wikipedia article on it:

Scientists taken were often involved in the Nazi rocket program, aviation, and chemical and biological warfare.

The operation was not solely focused on rocketry; efforts were directed toward synthetic fuels, medicine, and other fields of research.

Operation Paperclip was part of a broader strategy by the US to harness German scientific talent in the face of emerging Cold War tensions, ensuring this expertise did not fall into the hands of the Soviet Union or other nations.

Anyway, I don’t know that any of them ended up doing fucked-up stuff for the CIA, and was making a joke. But like many jokes, the kernel of plausibility is part of what makes it funny.