We’re aiming for this in the medium term, not for a specific year. Which gives us some room for manoeuvre. How long exactly is the medium term? That depends especially on the source of the shock.
A demand shock requires a shorter horizon for the policy response, that is policy should be less patient, whereas a supply shock may call for a longer horizon, and hence more patience. Wouldn’t it make sense to allow more downward scope in the inflation aim? The aim must be crystal clear, especially when inflation is low.