There is actually considerable precedent for what unions are seeking respecting minimum wage waivers. A number of states mandate minimum work standards dealing with required meal periods, breaks, uniform allowances, etc. (including California, whose wage orders are among the nation’s strictest). Many of these laws or regulations (again, including California’s) incorporate language like “except as provided by a collective bargaining agreement” after spelling out the mandatory benefit. Nothing out of the ordinary here; just the usual union “do as we say, not as we do” hypocrisy..
Sounds like unions are a lot like Conrgess. Exempting themselves from rules others have to abide by.