In my view, the surprise should be primarily confined to data or event surprises. That is, with a well-understood reaction function, the vast bulk of surprises should come from unexpected developments, not unexpected actions by the central bank. The amount and content of communication has been one of the most substantive changes over the past 25 years.
That has, in my opinion, been clearly beneficial for the accountability of the Reserve Bank, as well as the effective functioning of the inflation-targeting framework. That said, it is always worth checking that the increased communication is delivering signal rather than noise. That is, the quality of the message is more important than the quantity.