In formal methods, a subfield of computer science, we'd typically use the definition of non-determinism that is widely used within our own field. For example, see: https://cstheory.stackexchange.com/questions/632/what-is-the...
I don't think that link contracts anything. It just says that probability is a subset of ND but not vice versa. Which is true. But this is not the same as saying probability is not ND. Maybe I'm missing something...
By definition, if your outcome is a random draw from a probability distribution (known or unknown), you cannot guarantee the outcome in a deterministic manner; you can only guarantee that in the limit, a large number of random draws will follow that distribution (known or unknown). But that's not what one would typically call determinism.