Worst case scenario: Actual Arabian genocide, The mad Pasha extends the Armenian treatment to the entire peninsula, Britain and the Zionists fill the void of chaos that's left behind, or mop up whats left. Islam and Arabs are reduced to a barely talked about minority in their own home.
Best case scenario: Vastly, ASB, improvement of interfaith relations between Jews and Muslim, to the point that their practically indistinguishable. Israel is not a Zionist state in this world but an inter ethnic multi-religious federation, nominally secular. Jews and Muslims are one and the same, caring more for practical than religious needs.
I really don't know to be honest.