How is "battle royal" archetypal initiation story?
The theme of all initiation stories is self-discovery. Initiation stories are measured in irony and "thrownness": a naive protagonist is thrown into a "trail by fire." At the beginning of initiation stories, the naive protagonists think themselves better than they are, or they think the world safer or friendlier than it really is. The endings of initiation stories may vary: some protagonists learn from the experience; some are confused; a few remain naive; all are disappointed.
In "The Battle Royal" we have a naive narrator who thinks he is a guest of honor, but he becomes a victim of exploitation. He wants to be a young Booker T. Washington, and he thinks the group of white leaders want to hear his racial accommodations. Before this, however, he is stripped naked, blindfolded, electrocuted, and bloodied. His speech is an afterthought.
By the end, the Invisible Man is more confused than when he began: his self-discovery is that he is blind and invisible. The whites treat all black young men (aspiring Booker T. Washington's or not) the same; worse, they expect him to see the world through white eyes (as symbolized by the white blindfold).