Is that even possible for him to do without Arte giving him the okay? He had a contract that went through next season, he resigned. Isn't he restricted from taking the same position with another team? I've asked this before when someone else made a similar comment but, if he can just go sign on with someone else to be their GM, then what would keep guys from constantly quitting when a better opportunity arises?
Because of the possibility a GM can do exactly what you are talking about (and damage his previous team), I'm willing to bet he's in limbo for the next 18 months.