That's very similar to the editing mechanism in Stack Exchange sites; a low-rep user (or even an anonymous user) can suggest an edit which then must be approved

That's very similar to the editing mechanism in Stack Exchange sites; a low-rep user (or even an anonymous user) can suggest an edit which then must be approved by two high-rep users or by the original poster. Or any high-rep user can just edit it directly, although that would be a less attractive feature on a site like Hacker News.