It's not the same situation. If I bought my beer four weeks before the strike should I not drink it anyway. The beer is a manufactured good. Its is up to the people who drink the beer to decide. If I were a beer drinker I would buy a different beer. But I wouldn't quit drinking beer!
The casino provides a service to the people not a product. If this service were to have an impact on the safety or health of people then there would be other concerns like in the police or fire department. If you don't go to the convention because of a strike then you are the person who is out of your good time and you have only hurt yourself. If you cancel your room or banquet and tell the casino that it is because of the strike then this would help the employees. But with an arrangement between the club and the casino, If you do not go to do your trading and buying of chips you only hurt the club. The people who paid for their tables are the ones who loose. Could you arrange to have the convention moved to Laughtlin at the last minute.
David