(a) When the court obtains jurisdiction over a juvenile, jurisdiction shall continue until terminated by order of the court, until the juvenile reaches the age of 18 years or is otherwise emancipated, or upon the juvenile's death, whichever occurs first.
(b) When the court's jurisdiction terminates, whether automatically or by court order, the court thereafter shall not modify or enforce any order previously entered in the case, including any juvenile court order relating to the custody, placement, or guardianship of the juvenile. The legal status of the juvenile and the custodial rights of the parties shall revert to the status they were before the juvenile petition was filed, unless applicable law or a valid court order in another civil action provides otherwise. Termination of the court's jurisdiction in an abuse, neglect, or dependency proceeding, however, shall not affect any of the following:
(1) A civil custody order entered pursuant to G.S. 7B-911.
(2) An order terminating parental rights.
(3) A pending action to terminate parental rights, unless the court orders otherwise.
(4) Any proceeding in which the juvenile is alleged to be or has been adjudicated undisciplined or delinquent.
(5) The court's jurisdiction in relation to any new abuse, neglect, or dependency petition that is filed.