Because a huge part of politics are optics. As I said, he's not going to do a bad job, he's not going to do ANY job. These committees always end up the same way, a bunch of technocrats will write a 2000 page report suggesting recommendations to help with systemic racism and this Charette guy will present it to the national assembly when it's done.
Appointing a visible minority to "head" this project is a ridiculously easy gimme, the actual work is not going to be impacted in any way and it gives the illusion that the Government is taking the issue seriously by appointing someone who would have faced racism throughout his/her life.
Seriously how is this complicated to grasp? If I'm going to create a committee to investigate issues women face in the workplace, I would put a freaking a woman to head the project. Similarly, if I wanted to create a committee to implement new ways to improve living conditions in an Indian reserve, I would damn sure seek out a native who lived on a freaking reserve his entire life to lead the damn project.