This. The author obviously knows nothing about history since there was no Mandate until after WWI. I’ve heard some bizarre theories in my day but the idea there were no Muslims in Palestine is definitely one of the weirder ones. There have been Muslims there continuously since the 7th century. Europeans and Arab Muslims fought a whole series of wars over the issue - the Crusades.
And of course the Ottoman Empire was MUSLIM, although I understand fairly tolerant to minorities such as Christians and Jews by the 1800s (although historically they liked to kidnap boys from Christian areas and turn them into janissaries—the Sultan’s personal soldiers).