I hope it was seen as a joke!
Regarding your question: it's an interesting one. I think we'd inevitably have to rely on broad conceptions of types/functions to formulate hypotheses. A guy I used to chat to on reddit had an interesting perspective: he said that indeed, it all depends on perspective. Maybe Fe, from Fi's point of view, is self-centered in seeking external approbation; whereas maybe Fi, from Fe's point of view, is self-centered in remaining adamant about its values, away from external scrutiny.
Don't really know about the other functions and how they potentially impact self-centeredness. ID, any perspective on this as an expert function analyst?