His idea's to make a social network where toxic content's has lower viral coefficients. Censorship is certainly one path to this goal -- simply kill any objectionable content before it has a chance to spread.
How else could you make a piece of content less likely to spread? Display it less prominently. Warn people that it spreads negativity and they shouldn't propagate it. Automatically identify filter bubbles and occasionally include content with an opposing viewpoint.
The real problem is some/all of these measures may cost you users. How do you lower the viral coefficient of toxic information in your social network without lowering the viral coefficient of your social network itself?