I don't know how serious it was. In hindsight it was more likely that TypologyC was on the drawing boards and it was decided by elements within those in the know that extra incentive was needed to ensure that as many non-INTPs jumped shipped as possible once Tc was up and running. But yeah, there was quite an unpleasant little campaign of marginalization running at the end, including popular threads on why we don't want non-INTPs here and polls on which prolific non-INTPs should be banned to restore balance. I could go on.
There was also a strong element of this present, if you replace "girls" with "NFs" and "math" with "virtually anything abstract".