They didn’t know whether he was going to make it or not on Monday night. They did the right thing postponing the game and now there isn’t a feasible option to play the game.

The players just watched one of the teammates or competitors die on the field. They aren’t going to want to play and if you force them too its a bad look all around. Not canceling the game also means they have to make it up be either playing two games this week or postponing the entire playoffs by a week which is a logistical nightmare for everyone and for the two teams that have to play the make up game they will not be as well rested or prepared for their playoff game. If this happened in week 1 there would be time to make it up.