Arabs don't buy into Ummah Chummah because they will be a minority in front of South Asian and South East Asian Muslims who make up 50% of the population of the Ummah. Ain't no Arab wants to bend the knee in front of Paki, Indian, Bangladeshi, Indonesian or Malaysian Muslim who they view as inferior. Bring African Muslims into Ummah then it will be 75% non Arab Muslims in the Ummah. Well, they aren't going to bend the knee either in front of African Muslims who they enslaved few centuries ago.Pan Arabism/pan Islamist has always been a meme. Even under the first Caliphate, they spent most of their time dealing with internal squabbles and conflicts. It’s another gay pan-liberation ideology born of the 1960’s and it’s all fake.
Also, literal LOLz at the idea that Assad will ever even consider shaking hands with the House of Saud, Erdogan or Qatar after the shit they have perpetuated against Syria, leave alone some Pan-Arab wet fantasy.
Arabs even today aren't great fans of Turkey given their history with Ottoman Empire. For the Arabs in the Gulf they see themselves at the top of the pyramid as they think Islam is first and exclusively revealed to them. If there is a Ummah ever which I don't think ever going to happen then Gulf Arabs want to sit at the top like Kings and Asian and African Muslims at the bottom like slaves.