I'm sorry, but you're simply wrong. That's not Transhumanist philosophy. Read some of their literature some day instead of just listening to their wackos. Transhumanists want to eliminate death, because they believe it is a "disease," they want humans to adapt to alien environments, and they want humans to achieve "higher" levels of consciousness, whatever that means. What you're talking about is belief in the technological singularity, which is not universal amongst transhumanists, and which does not necessarily include cataclysmically fatal events.