Hmm interedesting. Ive actually never read the full study in the original pic since it's behind a paywall, and their focus seems to be slime mould growth as a "smart network" expression. I just presumed their shown autism/schizotypy chart was more or less established.
With that, i am not sure i understand your point though. You seem to be saying that schizotypy and autism are not in the same axis, yet you yourself say that they seem to be diammetrical and the pics you posted say so as well. So what is the difference between the x-axis on top then? If what you mean is that it's not so much a "schizotypy" axis, but a "default mode activation" axis, then sure ok, maybe that's more accurate since autism would be inhibitation, while schizotypy is overactivation. Still, the main point--convergence vs divergence-- would not change: 4chan is either over inhibited or activated with medium to average control, while reddit is mostly default with higher control (""book smart""" type).
Do clarify if i'm misunderstanding something though. Pic related is abstract of original pic.