My inside sources say if there is no settlement, there will be almost certinly some sort of job action from the referees. Probably won't be a strike because they wouldn't get paid and might get fired.
Right now the most likely action from the referees appears to be that the underdogs will win all games. Looking good for people that bet over on season win totals for bad teams and under for good teams. People that have tickets at monster payoffs on bad teams to win the Superbowl should start thinking about hedge strategies.