All hearings held in proceedings under sections 259.21 to 259.63 shall be confidential and shall be held in closed court without admittance of any persons other than the petitioners, their witnesses, the commissioner of human services or an agency, or their authorized representatives, attorneys, and persons entitled to notice by sections 259.21 to 259.63, except by order of the court. The files and records of the court in adoption proceedings shall not be open to inspection by any person except the commissioner of human services or the commissioner’s representatives, an agency acting under section 259.47, subdivision 10, or upon an order of the court expressly so permitting pursuant to a petition setting forth the reasons therefor. In a stepparent adoption, upon receiving a written request from a parent whose parental rights would be or have been severed by the adoption under section 259.59, the court or the commissioner may confirm in writing whether or not an adoption decree has been granted and, if so, the date of the adoption decree.