Earlier this week when MLS rescinded Aurelien Collin's red card, they stated that there would be no punishment for Birahim Diop on the play. That changed today when MLS announced that the red card suspension for Collin had been transferred to Diop. Diop will now miss tomorrow's game against New York.
In regards to MLS changing their mind, the league and US Soccer's hands were tied. According to the release from the league, "Because the misconduct was assessed and included in the match report, and the only reason Diop was not sanctioned initially was because of mistaken identity, the FIFA Disciplinary Code requires that Diop be issued the red card and serve the corresponding one-match suspension. Per the corrected interpretation, the MLS Disciplinary Committee did not have jurisdiction to decide whether or not Diop would be suspended."
The league's hands were tied by the FIFA Disciplinary Code. Still doesn't explain why, if the league knew of this, this wasn't announced originally when Collin's suspension was rescinded. Just another example that there needs to be some sort of review after games and some way to totally rescind cards or hand out cards retroactively, like to the instigator and diver in the incident, Benny Feilhaber.