Opt-outs are just a fancy name for player options, a contract feature that's been around for years. So team opt-outs do exist...they're called team options.Except that Sale would have to be crazy to opt out of the deal. The player is always looking out for his own best interest, not the team's. Now, if it were an opt-out either the team or the player could exercise (without approval of the other), that would be something!
It's all down to how the contract is treated for the purposes of calculating luxury tax obligations.