It is my belief that Araby should not be not considered as a possible faction supported by Creative Assembly. But before I get started in my argument, I support Creative Assembly and Games Work Shop if you choose not to consider Araby if it is for artistic reasons or vision reasons, I'll explain more in depth now.
I had several friends, both growing up and as an adult, from Iraq. I still remember very fondly having theological and cultural discussions on Fridays and Sundays in my unit and my apartment. They particularly enjoyed my company for this reason, Westerners have a tendency to very shy and sheepish about these topics due to preconceived ideas of what 'Middle Eastern' folk consider offensive. As a Westerner, I was considered very refreshing for that reason, no topic is taboo, faith is freely expressed and the flow and exchange of ideas is natural.
If Creative Assembly and Games work shop feel that they're unable to create content for Araby because they feel it is sensitive, I feel that they by default exclude inclusion. This is particularly sad, as during the time of the HRE, the Middle East was a flourishing time and place to be. It is that main point that I would like to focus on, the point where fear of causing offenses forces the option off of the table. If fear of causing offense is indeed the main motivation, I would encourage you to find members of the community who play, and members who don't, religious and secular for both counts. Then, speak with them about what they think is important to them about culture, religion and even ideas. It is my belief that if you brought people in, talked about including a fantasy interpretation of their culture and history, they would be either excited and offer to help, or excited and start offering ideas without consent.
Once again, if the reason is balance of the game or campaign, to many human factions or anything outside of cultural sensitivity, I respect and understand. However, if it is out of fear, then this is a huge mistake, and in and of itself is the offensive thing that you're trying to avoid.
I am looking forward to the Silence and the Fury, I hope you have a lovely day, please keep making a amazing product and building on an amazing world.