One of the best arguments against this type of propaganda is to look at what actually happened in places where they treat their workers more fairly.
Like, you hear people say that fast food would become prohibitively expensive if we raise the minimum wage, but when you look at countries where they have decent minimum wages, the fast food there is basically the same price. Maybe pennies more.
The best way to combat this propaganda is simply to experiment or call their bluff. You know, try it out and see what actually happens. When NYC does this and nothing bad happens, maybe that will be a clue to other cities.