The key element is the last:
In this way, would the Muslims living under the sovereignty of Britain, France, Russia, Serbia, Montenegro and their supporters deserve severe suffering if they fight against Germany and Austria, who are helping the Ottoman government, because it would be harmful for the Caliphate of Islam?The ruling Committee of Union and Progress (the "Young Turks"), were not terribly religious nor believers in Jihad in the current sense of the term, but they, and their German allies as well, had harbored a dream that the claimed authority of the Sultan/Caliph (though he was now largely a figurehead) might be used to persuade the large Muslim population of British India, of British-protected Egypt, of Russian Central Asia, and of French North Africa, to throw off the colonial yoke. The quote above shows they were emphasizing that Muslims were not only forbidden to fight against the Ottomans, but against their German and Austro-Hungarian allies as well. (Despite the mention of Montenegro and Serbia, there was no hint that Bosnian Muslims should rise up against Austria-Hungary. A Jihad dependent on Christian alliances.)
Answer: They would.
Although Russia and Serbia declared war on the Ottomans on November 2, Montenegro on the 3rd, and Britain and France on the 5th, Turkey did not formally reciprocate until November 11, though by that time combat had begun in the Dardanelles, the Caucasus, Mesopotamia and even Yemen. The declaration of war authorized by Sultan Mehmed (Mehmet) V did use the word Jihad, at least in the sense of a great struggle, but the religious sanction of the Sheikh-ul-Islam on the 14th was clearly aimed at the Muslim populations under British, French, and Russian rule.
|Sultan Mehmed V|
Despite his lack of real power he was the symbol of Ottoman authority, as shown in this German (I presume as it's in German; it could be Austrian) celebration of the Drei Kaiser Bund," showing Wilhelm II, Mehmed, and Franz Josef. It's obviously meant to flatter the Sultan, who had far less power than the other two "Kaisers." (Only Wilhelm II would survive to see the end of his Empire.)
The Shaykh-ul-islam who formally proclaimed the jihad is even more ephemeral. Ürgüplü Mustafa Hayri Efendi (who signs the Jihad fatwa in an Ottoman Arabo-Persian form of his name, (Hayri bin Avni Elürgabi), (1867-1921) having taken over the religious post in March of 1914; he would give it up in 1916.I don't read Turkish, but for those who do, you can find biographies here and here.