Hey
Done the test, http://image.prntscr.com/image/86a269bdb45740a9986d4ee8957b069a.png
Mifune/Kakuzu "dispersed buffs' is indeed a debuff. Which means the Immunity overrides considering it's first.
Now I can't comment on other versions of the game. I only focus on what we currently have.
Hopefully this answers your question.