Actually, Craig has no connection to the old show. Having Joey as his stepdad is the only degree of separation between him and Old School Degrassi, and it would be a stretch to use that as the connection.

As I mentioned in another thread, the only characters in Degrassi: TNG that have a connection to Old School (putting aside the Degrassi Reunion special, the White Wedding two-parter, and the two parter featuring Emma's birth father) are Snake, Spike, Joey, Caitlin, Mr. Raditch, Emma ... and the one guest appearance by Wheels ... and one brief cameo appearance by Yick as nothing more than a background character in "When Doves Cry" ... and Dr. Sally!