TimeQuest Asynchronous Interface Constraints

Note that the set_false_path is saying, "Don't analyze this path." So you're putting a constraint on the port that says not to constrain it. From a design perspective, having no constraint or telling Quartus not to analyze it is the same thing. From the perspective of completeness, having the constraint says that you've analyzed the signal and actively determined that it doesn't need a constriant. When you get handed a design someone else worked on(or when someone else gets this design someday) this is they type of thing you'll appreciate.