As said before the NBA is young compared to the rest of the leagues and there aren't many teams that have families following them for 4/5 generations outside of a select few. Compound that with how the NBA following skews national as opposed to local like MLB & NHL and to a lesser extent NFL and it's hard to imagine.
But there are some markets where it where it would happen. Been in the league a while, havent won in 40+ years, a source of civic pride. If the Knicks, Pacers or Trail Blazers won it would definitely be like this.