In this case, a few days before this post was made there was a "My Little Pony Coronation" event which included an advance screening of the episode (EQD covered it here, along with limited spoilers). So, basically, this guy wither went to the event, or got spoilers from someone who did. In fact, any spoilers that came out after this event probably have the same origin, and so should not be taken as evidence that the poster has insider information.

This person shall be known as Deep Throat.