Can a life estate be revoked if they can no longer live in the house and moves to a different state everything is paid for and up to date?

A life estate is a right to the use of real property for the duration of a person's natural life. It cannot be revoked unless the power to revoke for non-use was reserved in the document that created the life estate. Otherwise, you need to have the life estate holder sign a deed releasing their life estate in the property in order to clear the title.