Much more likely is that wikileaks assured him "Don't worry, it'll be fine." Wikileaks is much more concerned with getting lots of publicity than with actually getting him someplace safe (otherwise why would they tell everyone in advance what they are going to do).
He had to know that canceling his passport would be the very first thing the US would do.
He had to know that canceling his passport would be the very first thing the US would do.