“...because you’re basically taking away a constitutional right to freedom of speech...”
Hay uproar guy, please read this: “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.”
This says nothing about what the NFL or anyone else can make rules about.
Maybe when this entire kerfuffle is over, Americans who did not learn civics in school will finally learn what rights the Constitution actually guarantees. Schools spend too much of the “social studies” class time teaching that the USA is an oppressor nation. Sadly that is not sarcasm.