I think the object of an operation chaos is to deceive the party about the actual level of support their candidate has, not just make them mad. It is intended to cause over-confidence in the candidate himself (or herself) and thus set the party up for a big November surprise.
Overconfidence, or perhaps division and pandemonium.
I did consider that making them mad might backfire, but so might promoting Sanders. As likely is that it further, perhaps fatally, fractures the ‘Rat party by intensifying the infighting over who is best to face Trump.