Yep! Ever seen Pulp Fiction? Do you know what's in the briefcase? No one does. It's a McGuffin. The Torment Nexus is also a McGuffin, it's a poorly defined thing that the actual definition of is irrelevant to the plot, only how it creates motivation for the characters.

In this joke the "Torment Nexus" by name is clearly something you don't want, no one wants to be tormented. It's also the McGuffin because something named a Torment Nexus would HOPEFULLY be something someone wouldn't build, but the joke is "hey this guy went and built the horrible thing we didn't want!"

Ever heard anyone make a Soylent Green joke? Same thing. All we know is that "soylent green in people" but we don't know HOW it's people, but it doesn't matter because we simply don't want to eat people under any condition.