The same goes for the title. They will almost certainly be given some level of approval as a courtesy, and if they dislike the design or the title, that will be taken into account as well. But in general? It's not their place.
Perhaps it appears ridiculous that an author, who has conceived up an idea, written thousands of words, and gone through several rounds of edits to bring their idea to the world, will have little voice when it comes to packaging up the final book. But, to that, I say go to Amazon and look at some of the self-published book covers and titles for sale. You'll undoubtedly find a few good ones, but the vast majority look like they were created in Microsoft Word