I think maybe what I had in mind with my original comment was something like: “There’s a high probability (maybe >80%?) that the future will be very alien relative to our values, and it’s pretty unclear whether alien futures will be net positive or negative (say 50% for each), so there’s a moderate probability that the future will be net negative: namely, at least 80% * 50%.” This is a statement about P(future is positive), but probably what you had in mind was the expected value of the future, counting the IMO unlikely scenarios where human-like values persist. Relative to values of many people on this forum, that expected value does seem plausibly positive, though there are many scenarios where the future could be strongly and not just weakly negative. (Relative to my values, almost any scenario where space is colonized is likely negative.)
I think maybe what I had in mind with my original comment was something like: “There’s a high probability (maybe >80%?) that the future will be very alien relative to our values, and it’s pretty unclear whether alien futures will be net positive or negative (say 50% for each), so there’s a moderate probability that the future will be net negative: namely, at least 80% * 50%.” This is a statement about P(future is positive), but probably what you had in mind was the expected value of the future, counting the IMO unlikely scenarios where human-like values persist. Relative to values of many people on this forum, that expected value does seem plausibly positive, though there are many scenarios where the future could be strongly and not just weakly negative. (Relative to my values, almost any scenario where space is colonized is likely negative.)