Rejection is not expulsion.

Expulsion means being removed from a community. When the community expels you it sets itself as a unit against you, who are stuck apart from the remaining community and separated from as it if by a barrier.

Rejection is merely not being accepted. When you are rejected it need have no other consequences besides your not being accepted, but it can.

Expulsion is a painful and consequential form of rejection (though the experience of expulsion has properties other than those of rejection, to wit: loneliness, exile, survival, shame, guilt, culpability, accountability, solitude, self-destruction, seclusion, fear, uncertainty, doubt, and others), but not all rejection is expulsion: much of it bears few or no consequences.