Board Thread:Questions and Answers/@comment-24098614-20140928220912/@comment-8986886-20140928234049

This was already explained to you in another thread. There is a microscopic possibility that Ichigo may become so powerful that he can't go back home. Shunsui felt that he had to prepare Ichigo's friends for that possibility, in case that were to happen. I'm sure that Ichigo has no intention of staying in Soul Sociey for the rest of his life, if he has a choice in the matter.