This experiment presents a couple of possible outcomes in addition to fewer uncivil posts.
First, it will be interesting to see if those who receive personal gratification from flaming someone will receive enough self-satisfaction from a civil disagreement to keep posting. It could be the loss of the "rewards" that go with blasting posts will negated the attraction. No loss if that happens.
The other phenomena is the "honeymoon period". I suspect that some people are on their best behavior as the process rolls out. Eventually, some will push the system. At some point there will be a loss of posting rights for a few.