Can have religious connotations. In Genesis, God destroys a the Tower of Babel which man is building in order to reach the heavens. He also scatters man across the world and gives them different languages so that people cannot communicate with one another.
Describing someone as a 'linguist' suggests he is one who can unite mankind once more, and free him from oppression. Potentially, he does this through his poetic skill rather than through speaking all the world's languages.
Of course, it's used a bit more lightly than all that...
That rapper is a linguist.