Ironically, it was Kanye West's tracks NA requested. West, you remember was the one who had an epiphany about loving homosexuals and eschewing homophobia. Consequently, he issued a stern command to the rest of the hip hop world: "yo, stop it, fam."
Perhaps the show's creators interpreted that as a sign to merge the two warring worlds in their brave new show. Not! Def Jam flat out rejected the request. I can understand why. While I am no fan of the hard core rapistas, I can see why they want nothing to do with the swishy, girlish, effeminate nature of Noah's Arc[see the trailer, if you dare]. The show's four main characters are little more than reverse drag queens. Men acting like women who dress like men? The last episode even had the characters actually do a transvestite musical romp.
And they want Hip Hop tracks behind that kinda of stuff? Its like playing The sound of music behind the Shaft movie.
SOVO has a longer version of the controversy here.