I found it interesting that these are the only two devil fruits confirmed to be unaffected by Haki.
Of course, it makes sense, given the conceptual nature of Bartolomeo’s Bari Bari No Mi and Buggy’s Bara Bara No Mi. With physical power fruits, it’s understandable that Haki can counterract their power. But if the fruit has a conceptual aspect to it (like “being resistant to cuts”) then it’d be pretty silly to have the fruit be damaged by cuts just by using Haki. It would also make it virtually useless, since everyone has Haki at this stage. Same goes for the barrier. It’d be pretty dumb to have an unbreakable barrier break just because someone has strong Haki.
But what makes it really funny to me is that both these fruits are in the hands of joke characters, so it’ll be really interesting to see how they play out.