It is important to select and fight current battles based upon the reality of our cities, not based upon how segregation worked prior to 1954.
I am not certain how this decision will impact mega cities like New York, Boston, etc. In mid sized cities like Sacramento, Seattle, Louisville, all of the high schools are integrated. In Sacramento they range from 25% Latino, 23 % African American, 26% Asian, 24% Anglo. Each category ranges up and down 10- 15 %. Elementary schools are far more diverse. So, each school will have a minority population of at least 45%. The argument is that an Anglo student should not be allowed to transfer out of a school if it impacts the demographics of the school. So, the debate is should a student be restricted if he chooses to move from a school that is 20% Anglo to a school that is 40% Anglo. Unlike prior to Brown: there are no all white schools in the cities. There are overwhelmingly white schools in the suburbs, but since these are in separate districts, the court long ago decided that governments could not mandate across district integration.
The Brown decision said that separate and equal was never equal, and it mandated forms of integration. What we have now is integrated and unequal- and the urban schools have a series of crises. Until we begin to provide quality schooling in our urban schools, until we act upon the unequal part of the Brown decision, we really are not making much progress.