(a) The court may not appoint the department or the Department of Aging and Disability Services as the managing conservator or guardian of a young adult.
(b) A court may not order the department to provide a service to a young adult unless the department:
(1) is authorized to provide the service under state law; and
(2) is appropriated money to provide the service in an amount sufficient to comply with the court order and the department's obligations to other young adults for whom the department is required to provide similar services.