Actually it can, you even deny this point yourself in second paragraph.
What did I conclude again? Escaped my notice again. These runaway conclusions will be the death of me.
To answer your suggestions - it sometimes happens on MBTI forums that people google something like XXXx + XXXx and revive a five year old or so thread in their first post. The use of 'duality' in this context doesn't make it impossible, although perhaps less likely.