Interesting choice, though if he did get the part, then it's unlikely Williams would be cast as his sister -- or vice-versa. But it's good that they're open to different options rather than defaulting to white.
I had to look up "SMH," but apparently means "shake my head" as if in disapproval. I don't see any reason to object to Jordan being considered. He was good in Chronicle
, and he has the right kind of charisma and attitude for Johnny.