Yes. "Want" being the operative word. It's a preference being demonstrated; a goal being presupposed, not a norm. If you had said "ought" instead of "want", you'd have been claiming that a norm was being presupposed, and I would have disagreed.
This is now just nit-picking but prefering a goal, is also accepting a norm (I ought to achieve the goal). Let's not dwell on semantics though.
This whole paragraph can be reduced down to: "When we engage in discourse to resolve a conflict, we demonstrate a preference for engaging in discourse to resolve a conflict." Which means the paragraph can be removed completely, since that is exactly the conclusion you reached at the end of the paragraph immediately before it! ("The implied goal is that participants prefer to resolve their dispute without resorting to violence.")
OK, there are a few things that add information in the subsitution. The purpose of the paragraph was to show a context, and clarify the link between saying something and "engaging in argument" with all the presuppositions. So I'm not sure it's redundant. but that really doesn't seem to be worth not making an effort to clear such minute details.