Schools Chancellor Carmen Fariña last Thursday made public charter-school families a promise. At a town hall meeting in Brooklyn, she told parents of rising middle-schoolers sitting in the audience that “we have full expectation to, within the next week or two before Thanksgiving, giving you a placement, and we will be announcing it soon.” Her words were certainly a step in the right direction. Unfortunately, as public-charter families have learned, talk is cheap when it’s coming from the de Blasio administration.