It really isn’t that simple. The north didn’t have as much strict segregation but in a way it was because they didn’t have to. Economic pressure reinforced by subversive hiring practices, prejudice in housing and hostile attitudes kept black communities tight knit and localized which meant you didn’t have to have specific “Colored schools” because they were created by these forces squeezing folks together into controllable blocks of population.

In the South the fall of segregation had a number of nasty fallouts which harmed black communities as well. When they merged the systems there was a historicly significant loss of black teachers. People got up in arms over really stupid questions like “What if my menstruating daughter had a black male teacher” and that prejudice ensured that a lot of the teachers who understood the challenges of being black in America were no longer in a position to help students.

This meant that effectively in the North segregated schooling continued to be a thing in practice but not in name while in the South it wiped out infrastructure that was helping black students succeed. It was handled incredibly poorly and was not unambiguously good but it did change a lot of the legal categorizations and is considered a win.