If you should say that he will appear despite his fear for his life, it follows that his fear for his life does not warrant his occultation in the first place, and thus, he must appear. If you say that he will not appear and the duties that have not reached the Ummah are not binding, it is an assertion against consensus (Ijma), which says that everything the Prophet (s) has introduced in his Shariah and has explained it, is imperative and binding on the Ummah until Judgment Day. If you say that the duty is still binding, you are suggesting a duty that is beyond our capacity and an obligation to perform a task, which we do not know.