Many of the Transformers in the original cartoon and comic fit various cultural stereotypes.
Jazz and Blaster have always sounded like urban blacks. Blaster spends most of his time break-dancing ffs. I never heard anyone complain about it until Michael Bay made his little movie.
Really? Jazz was voiced by one of the greatest legends of all time, Scatman Crothers. There is a reason why he sounded like an urban black...because he was voiced by an urban black man.
I don't know about Blaster and Buster Jones, but Buster has played some black characters as well.
Plus, you know BOTH OF THEIR HISTORY FIT WITH THEIR VOICES.