That's not strictly correct. Any contract can have clauses which are unenforceable because they are unconscionable in their field of operation ie they provide an outcome inequitable to the parties. The afl even as participant to the contract would be so only to the extent of ensuring compliance with afl rules which would include TPP. The afls participation would, I suggest, be limited were they to try to interfere with ordinary financial dealings between parties (player and club) acting at arms length to each other.
The afl are already on extremely shaky ground because the whole concepts of drafts and TPP and it's various nuances are unreasonable restraints of trade which, if contested, would fail to be enforceable. There is clear precedent that supports this. Fortunately the afl, clubs and players voluntarily cooperative within this legally unenforceable framework simply because no one has ever challenged it's validity in legal context. That is why , as one example, when swans were slapped with the trade ban a SeniorCounsel came out saying you can't do that- same reason unenforceable and unconscionable
The afl THINK they have power and own the game and it's participants but the truth is that the whole edifice is one legal challenge away from disintegrating.
I don't disagree with you, however that is just pure speculation of what might happen if a player or club wanted to legally challenge the current rules of the competition.
The fact is there are rules in place to ensure the integrity of the restricted/free agent process and those rules are applicable to all clubs.
There is no way the AFL will allow a change to the TPP reportable amount for a restricted/free agent player half way into or at the back end of the contract.