Dr Tolian Soran...

...is still alive. He entered the Nexus, at the same time as Picard. Just because Picard left the Nexus at a poor choice of timing, and changed events, doesn't mean Dr. Soran was also taken away from the Nexus. He has been inside the Nexus the entire time, what is a curiosity is if he has any idea his alternate self was killed in the missile explosion.