Is it true LIGHTSKINNED GIRLS AND MIXEDGIRLS get chosen mostly for rap and hiphop vids?

was watching a doentary on youtube by a women named joy daily and in a way she made a point BUT when i was little i saw alot of darker girls in videos. Also she talked a about a video called "pretty girls" by wale and she said all the girls are mixed, white/latin.or lightskined blackgirls and 3 were mabe black. i watched the video and i loved it because i saw thick girls, a cuple darkskinned girls pretty lightskinned girls and 1 whitegirl and 2 mane latin chicks and it actually was diverse. Also i have heard at the castings alot of darkskinned firls dont show up...mabe there discuriged because the slave mentality about light is better?..idk but i dont have a problem with dark girls and ive seen hot dark girls and ugg lightskinned and mixed girls lol ..but what her point was the black lightskinned girls in the video were light and you couldnt tell what race they were all you new is they looked alittle black.....is it true?