The title is pretty sly in mixing both past and present tense interpretations. Hard to guess whether it was going to be Hoover's infatuation with the civil rights movement or some current day addition to domestic spying shenanigans.
I'm not 100% sure, but I believe formal American English is meant to be rigorous in treating organisations as singular rather than plural. Hence if the title was meant to refer to the present, it should have read "How the FBI Pre-reads African American Writing".
This is in distinction to British English, where it's often a matter of house style, or even dependent on context.