This change effects Regional championships only (Asia-Pacific, European Championship, Middle-East championship, and current-vapor-championship CNAR). It has no effect on any national championship series, including the US or BRC as the national sanctioning bodies (SCCA, MSA, etc.) determine what classes are legal for the national championships. The Australian championship will have Group N as its top class starting next year, but that was already announced a long time back. Should be pretty boring spectating...