Effective at 12:01 a.m., April 1, 1975, the Commissioner of Children and Families shall assume, and the Commissioner of Social Services shall cease to have guardianship, as defined in subsection (a) of section 17a-90, over all children who on that date, by virtue of any order of the Juvenile Court or Superior Court, are wards of or committed to the state of Connecticut or the Commissioner of Social Services. The Commissioner of Children and Families shall thereupon assume all liability and responsibility for such children, and exercise such powers, duties and functions regarding such children, as the Commissioner of Social Services in his or her capacity as guardian may now or hereafter have, except to the extent that the federal government may require that any responsibility for children be retained by the Commissioner of Social Services as a prerequisite to federal reimbursement of state expenditures for such children under Title IV-A and B of the Social Security Act. The Commissioner of Children and Families may delegate any power, duty or function regarding such children, except for consent for adoption, marriage and joining of the armed services and except to the extent that the federal government may require that any responsibility for children be retained by said commissioner as a prerequisite to federal reimbursement of state expenditures for such children.