Now you are just being obtuse.This is 100% incorrect. If I contract with you to pay you $10 a week to post on this message board - guaranteed money or not - and I then, without your agreement outside of any rights established in the contract, say "I am not paying you $10 a week to post on this message board and you are free to post elsewhere but you will not be posting here" irrespective of whether I can or not legally, I have unilaterally terminated the contract. This a is common and simple idea under contract law.
In your example, I would then have legal recourse to remedy any damages incurred by the contract breach, whether that be by arbitration, or lawsuit.
Do you see a lot of that with players/teams?
The answer is no, because teams do not unilaterally break contracts. If they did, teams would be sued on a regular basis.