Even if almost everything you say here is right, it wouldn’t mean that there is a high probability that if you are killed in a car accident tomorrow, no one else will think about these things (reflective decision theory and so on) in the future, even people who know nothing about you personally. As Carl Shulman points out, if it is necessary to think about these things it is likely that people will, when it becomes more urgent. So it still wouldn’t mean that you are the most important person in human history.
Even if almost everything you say here is right, it wouldn’t mean that there is a high probability that if you are killed in a car accident tomorrow, no one else will think about these things (reflective decision theory and so on) in the future, even people who know nothing about you personally. As Carl Shulman points out, if it is necessary to think about these things it is likely that people will, when it becomes more urgent. So it still wouldn’t mean that you are the most important person in human history.