True, however it should be remembered that Islam was viewed very differently in the West when the Dune nooks were written. Kind of a cute religion or primitive peoples. No kind of a threat. Their religion has also incorporated Buddhist and other elements.
In the Dune books, Herbert drew on a number of themes from Islam, Judaism and Zen Buddism. The term “Kwisatz Haderach” to describe a messiah figure is a transliteration of a Hebrew phrase. The history of the Fremen in the books seems to mirror the ancient Hebrews/Israelites somewhat. Although their religion is rather Islam-like with some Zen elements. They do use the term “Jihad” a lot, but the books were written well before the term took on the more threatening context of recent times.