I don't follow. The null hypothesis can be phrased in all sorts of ways based on what you want to test - there there's no effect, that the effect between two groups (eg. a new drug and an old drug) is the same etc.

then you conclude "our data was unusual, rather than there being no effect" when you get data with probability < .05 if the Sun hasn't exploded.

I don't know that my frequentist example does conclude the 'data was unusual' rather than 'there was an effect'. I am not sure how a frequentist would break apart the disjunction, or indeed, if they even would without additional data and assumptions.