> Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
So, did Congress of the USA have to do anything about it? No, "free speech" does not mean you can say anything you want without facing consequences from people who hired you or your friends. Blizzard hired player to play in tournament, and they can fire him if they want. There is nothing illegal in Blizzard's actions.
Morally, though...