I disagree. I think it benefits an actor to know his or her type. It helps to market yourself. That certainly doesn't mean that you can't play or audition for other roles. You have to tell directors who you are and what can you do. It won't do much good if the director sits there and thinks, "Great! I have no idea how what role for you though." But if you know your type you can audition in a way that will inspire directors to realize the roles you can play. I think I might be rambling at this point, but I had a really inspirational theatre professor explain this to me. You have to think of yourself as a small business and know how to market yourself. Knowing your type helps more than hurts.