It's the same for all those "progressive" causes. It's cognitive dissonance, they are trying to rationalize why some groups of people lag behind in certain areas, so they end up overcompensating.

They want to normalize this narrative about africans being the best warriors, who only lost because white people had guns. They want you to believe Yasuke was this revered figure the japanese people embraced and he became a samurai because just how competent he was when given a chance. When in reality, yasuke was kept around because he was an oddity, he wasn't a samurai, he was a poor warrior, to the point the real Mitsuhide let him live and sent him back to the portuguese because he wasn't a treat to him.