Bree Newsome, right, of Charlotte, N.C., is taken into custody after she removed the Confederate flag from in front of the South Carolina Statehouse in Columbia on June 27, 2015, in the aftermath of the attack at a Charleston church where a white supremacist fatally shot nine parishioners. (Bruce Smith / AP) Antoine Fuqua’s “Emancipation” is yet another movie about slavery. Our Black colleagues express a resounding fatigue with films on Black oppression and triumph. Watching these films is stressful, and people grieve those ancestors brutalized for profit and pleasure. But the main reason these movies drain so many people...