This argument doesn't make much sense to me. You can definitely associate a probability based just on the measured data. What if you measured 5, 5, 5, 5, 5, 5,5 (1000 more 5s) , 5, 999999999? I think it's pretty intuitive to say that 999999999 is unexpected relative to the 5s. And you certainly can have expectations that are generated purely based off of the measured distribution and not off of some theoretical model.