Headlines get changed to things that actually reflect the link's content all the time. Is flagging not a way for users to try to get that done? (I would have guessed so, but I honestly don't know. I certainly didn't flag this post.)
Flagging is commonly used to de-rank articles people disagree with, and considering the initial comments in the article, I’d eat my hat if people flagged it in good faith based on the headline alone.