Most Americans dont even know what a Jihad is beyond a word used on fox news from time to time.
I think its pretty obvious why they changed it to crusade.
They are making a few changes so the complex world of Dune isnt so complex to a viewer so the film actually has a shot at making money otherwise it would just be another bladerunner 2049 financial flop because the average viewer would rather watch marvel superhero films than support a thought provoking sci fi epic.