DeFord Bailey was more than 'mentioned', actually; he was given fulsome treatment - bio, photos, music. Uncle Pen's relationship with Bill Munro was discussed, although I don't recall his race being mentioned - was he Black? Rhianna Gidens was commenting. Merle Travis and Elvis weren't featured in the bit I saw, nothing said about their influences.

Why would you "doubt there's a mention of African-American country music performers", just out of curiosity?