It depends what you mean by "treat favorably." If a male IN tends to have fellow males as friends, that doesn't necessarily mean he's "sexist," and if he tends to befriend fellow N's (or fellow IN's), that doesn't necessarily mean he's "typist" — although it would arguably deserve to be called typist to the extent that his decisions about who to befriend are based on unwarranted type-based stereotypes.
I'd say my closest friends have always tended to be N's, including in the years before I knew anything about the MBTI.
When you refer to "treating one type favourably over another," do you have any specific kinds of conduct in mind?
As a side note, and for what it's worth, the official MBTI folks have made it clear they consider it inappropriate and unethical to use the MBTI in connection with hiring, firing, job placement and/or promotions, and also consider it unethical to require any employee to take the MBTI in the first place.