Fox of course could be traded, just like Kravtsov. But the point here is that Kravtsov has a contract to play in the NHL next year, and unless we trade him for absolute pennies to a team that will let him stay in the KHL another year, he is contractually obligated to report to his NHL team next season.
If he told the Rangers he wasn't going to report, I fully expect they'd treat him like Nick Jensen and just hold onto his rights until they expired. I don't think Gorton would allow a prospect to dictate the situation to him.