Leaving aside the relevance of an Alaskan newspaper talking about local Seattle politics, their only source is a news article from Seattle written the week of the law taking effect.
As I said in my original comment, show me something that isn't from the first couple of weeks after it took effect. Preferably something scholarly, not just anecdotes from a newspaper
And besides, what's the alternative here? Don't protect employees? Let them work below minimum wage?