Not true. There are Afro-Arabs in most of these countries. The thing is they have been so dehumanized and disenfranchised it is as if they don't exist. I believe they tend to know their place too.
I do more than a fair bit of advocacy for Palestinians and as a black person, I am always stunned that the face of the struggle is "white" Palestinians, yet there are Afro-Palestinians there. No one ever sees them. The first time anyone got a glimpse of them, many were surprised because they never knew they existed...it was mind-blowing.
Racism does exist in the Middle East and I believe it is worse than in the white majority countries because it is in the shadows and the pretence of being harmonious societies is upheld. I would love to see an Afro-Arab become President in any of these countries.