It's not true.
But there is a problem with public schools with failing young black boys. Teachers end-up all joining in on the culture of not caring for the student progress. They already come in assuming the worse out of the them and not being equipped with the right tools to help the students out.
I had to file a suit against a school over here because 2nd to 4th graders were not getting homework from the teacher. The school was angry at me and our organization for expecting more from them even if the home-life for these boys weren't also encouraging them to do their homework. It's never an excuse not to prepare them at the same rate and expectations that other students get. An endless remainder we need parents to be in control of who gets to teach their students.