I think, at its core, Austrian economics holds that money should emerge as a market goo, not something decreed by the state or defined by an arbitrary quantity. It's just that, in a free market, individuals are more likely to gravitate toward harder forms of money, which often means something with a limited supply.

Also, there's an important distinction between deflationary prices and a deflationary economy. The two are often conflated, likely because deflationary economies frequently result in falling prices. But they’re not the same thing.