What is so "Austrian" about the Austrian Theory of the Business Cycle? Mises actually asked that question in an article published in Economica in 1943. To quote him, "Why call this monetary or credit expansion theory of the trade cycle "Austrian" or "Austro-Wicksellian" theory? ... But why forget that this theory is the continuation, perfection, and generalization of the Currency theory? Neither Wicksell, myself, or Professor Hayek, have ever forgotten to emphasize this point."
Since 1943, there have been several different contributors to our understanding of the monetary theory of the trade cycle. And I think Mises's point is well taken given the modern evolution of economic thinking. It is not an "Austrian theory" as much as a monetary theory to be contrasted with a "real theory" and/or some variant of an "underconsumption theory", etc.