Can we just agree that EVERYONE Austrian or Keynesian expects the exchange rate for real goods and services against BTC will rise and BTC's will buy more in the future.  All you Austrians have been arguing that will happen, have been advocating people hoard coins in anticipation of future consumption higher then the consumption deferred to buy and hoard the coins and so far (outside of some crashes) your prediction has been correct, BTC appreciated massively.

Now if a Keynesian when using the term 'deflation' means that price appreciation then by golly they are correctly describing BTC by what that word means to THEM.  If someone else with this weird idea that these words mean only nominal changes in money supply says BTC is inflating then yes they are also right by what that word means to them.  All we have here is a disagreement over what words mean, not the nature of BTC which everyone agrees on undeniable fact, that of growing supply and appreciation in value.

Now I'm going to argue that the so called 'Keynsian' (really everyone excluding a few wackos) definition of inflation/deflation is correct.  Why because it actually MEANS something to an economy and an individual, where as the nominal money supply tells us nothing about an economy or what to do as an individual.  Real inflation is an incentive to spend, real deflation is an incentive to save, BTC clearly falls under that latter kind of incentive structure (the Austrian and Keynsian would now have an actual disagreement over if this is good or bad).  If I make a statement about nominal money supply while ignoring the population of users, the quantity of production and the demand for consumption of those users I've ignored so many CRITICAL factors that I no longer say anything meaningful about the signals being sent, are individuals under an incentive to spend or to save, I haven't said one way or the other unless I make the assumption that ALL the other factors are constant which this narrow definition explicitly excludes if it mean ONLY nominal money supply.

And you know who else agrees with Mr. Keynes on this definition, VON MISES, quoted directly from Theory of Money and Credit, at http://archive.mises.org/19306/inflation-and-deflation-austrian-definitions/