One of these situations is not like the other. Kane was still playing and because of that had to wait 3 years to get out. Trouba probably saw that and said I would rather give up a year than sit in Winnipeg for the next 3 years while Chevy sits on his ass..
So, how is it different? Trouba can't make the Jets trade him. He'll sit as long as the Jets want him to or until he signs and plays with the Jets. Exactly the same.