They could at least factor it in selectively, in obvious situations. For example, all categories in jeopardy that contain a quoted string include that string in all of the answers. Wouldn't be too hard to use that information.

edit: furthermore, sometimes it's impossible to narrow down the answer if you don't understand the category. For example, if the category is '"C" you later' or something, there might be like 8 possible synonyms that fit, but only one starts with a "C".