In "The People Could Fly," we witness an enslaved people remember the power that has been inside them all along. For a long time, they've been convinced that they are at best ordinary, though they're primarily treated as even lesser than that. But you want to know what? Many of them can actually fly, which is more than the white folks who've been violently oppressing them can say.
The title, then, refers to enslaved people's abilities to be free. For more on flying, be sure to check out the "Symbols" section.