That just leads you down the road of discarding probabilities. Since something either happens or doesn't happen, the probability is either 100% for the things that will happen or 0% for those that do not. This is not a helpful position to take, although it is technically correct, in some not very useful sense.
Humans are good at dealing in counterfactuals. 'What would have happened if I hadn't missed the bus?' is a useful question to ask, even if you did miss the bus. What would I be like if I hadn't gone to university/had taken that job/never killed my parents? Obviously the 'I' in those questions cannot be you, exactly, since you did or didn't do those things. But it's still a useful concept or thought experiment, and can give us valuable insights.
The commenter is using 'I' in that counterfactual sense. And certainly, I understood what they meant by it, so they were successful in communicating (at least, to me) which is what matters with language.
Which is what I was answering. You can't pick a human at random including from the future, unless you're outside the system somehow.