Only if the market goes up enough vs the other neighborhoods and what would have happened. Which maybe you can argue it does. I'm not racist enough to believe that the presence of people with black skin is that detrimental to property values. It seems clear that redlining is about class more than race.

You still have the problem that subsidies are generally thought to cost money. If redlining makes the city money it goes from "this is evil and doesn't work economically" to "this is evil but it makes money."