There are several things wrong with this post. Firstly, I'm sure different people would react to being convinced their moral philosophy was wrong in different ways. Some might wail and scream and commit suicide. Some might question search further and try to find a more convincing moral philosophy. Some would just carry go on living there lives and not caring.

Furthermore, the outcome would be different if you could simultaneously convince everyone in a society, and give everyone the knowledge that everyone had been convinced. Perhaps the society would break down as the police and institutions upholding the law abandoned their tasks due to both apathy and a desire to capitalise on the new state of affairs, with no guilt. Who knows.

The fundamental flaw of this article is that it asks us to consult our intuitions about what would happen if so and so. Consulting our intuitions is something I believe this site shuns, so it is quite hypocritical that the author has requested we place so much emphasis on them in this instance. Furthermore, anyone answering this question who believes in moral eliminativism has a confirmation bias to say 'nothing would change' as this is seen by them to support their beliefs.