The Comets name comes from the old Clinton Comets of the Eastern Hockey League (the league Slapshot was based on) from the 1950’s through 70’s. They played at the Clinton Arena, a small hockey barn from the 1930’s which is still in use after getting upgrades from winning the Kraft Hockeytown contest.
Clinton is a suburb 14 minutes outside Utica, so when NJ moved the Utica Devils to Binghamton, Vancouver moved in and they were renamed the Comets as a homage. When NJ moved back they just switched colors but kept the name.