Is this considered Work Discrimination?

I have worked for this restaurant for 6 years. They just recently added the rule that you must ask a manager to go out and smoke. Ok no problem. From what I was told by other employess it was because people would go out and smoke in the middle of a rush which isn't cool. So the reason for the rule was to make sure that all stations were manned and the customers didn't suffer. I then asked them if our dishwasher had to ask to go and smoke and he stated "No one cleans like she does" which is true. She is one of the best workers we have. It has been stated by our reginal manager that they are to make sure she doesn't quit as she helps us get the highest scores for cleanliness on our annual store reviews out of 100 stores. I have been told by my Kitchen Manager as well that if any employee does anything to make her quit the employee will be fired on the spot. I love her to death and we have an awesome work relationship and this is not to spite her. So I challenged my Kithchen Manager with "Thats not right. It is discriminatory the rules need to apply to everybody" He then looked at me and then stated "Well I'll just change the rule to those that clean the most won't have to ask to smoke" Can he do that when the rule has been in effect for 2 days already? Needless to say I am a little angry. This rule has been in effect since Thursday for the purpose of making sure all stations are manned when we are really busy which is fine by me. The thing I have an issue with is EVERY employee MUST ask a manger. I have talked to a few other employess and they are a little upset as well. Our city also just went to no smoking in restaurant and bars and yet our General Manager thinks it's ok to smoke in the Employee Bathroom. Is this a case of discrimination in both instances? Do I have any recourse? Or do I have to just bite the bullet?