Put that as a percentage. Better have a lot of zeroes after the decimal point
There will be no cancellation, and the boycott numbers are probably stable. Anybody who is not pissed by now will probably put up with whatever they do. I know plenty who are putting up with it.
This sounds like a threat to me that all black players will kneel or do something else disrespectful. Then it would be on the owners as how to respond. Suppose no disrespectful player plays. There might not be enough players to play the game, so the game is forfeited and the fans leave the stadium PISSED.
Since the threat is league-wide, this could happen in multiple cities.
So, I don't put the percentage very high but I would give it a 5% chance of happening.