Correct. Marvin "Opted in" to his contract, or he will if he hasn't yet. He signed that deal with Atlanta and the Jazz assumed it when they traded for him. So it is not up to the Jazz whether he is on the team next year. They would have to trade him to unload his contract. Furthermore, his contract in no way hurts the Jazz right now as they are so far under the salary cap that it is irrelevant.
.
The Jazz are probably looking for more contracts similar to his with players that are not worth them in an attempt to get future picks or different players with value.
Ok thanks for clearing that up. It looks like AK47 "opted out" on the other hand cuz now he is on the free agent list not that the Jazz want him.