I’m not sure how accurate this is but I have heard that the referees invited to interview to move to SG1 are Harrington, Gillett, Brooks, Stroud and Salisbury
FL to SG2 are Hicks, Madley, Busby, Drysdale, Bramall and Coy
FL AR to SG2 I have only heard Hunt and Liddle (I’m sure there are more)