That's a ridiculous constraint to put on the freedom to enter into contracts.
For arbitrary contracts I would agree, but I think increasing the limitations in severance agreements soecificallt makes sense. There are already certain requirements (at least in California) for severance agreements and I think limiting the duration of non-disparagement clauses to 1-2 years would be a positive change.
The government enforces contracts, so it gets to choose which contracts it enforces. Without a functioning judicial system (and a law enforcement system to enforce its verdicts), a contract is a piece of paper.
Plenty of contracts benefit both parties but are bad for society as a whole, and if the government pre-signals which sorts of those contracts it will refuse to enforce, this is good for society.
IMO, "freedom to enter into contracts" isn't actual freedom, for the same reason that the MIT license isn't more free than the GPL despite it allowing more behaviors: in both cases, it's basically "permission to have your freedom taken away".
Article I, Section 10: “No State shall … pass any … Law impairing the Obligation of Contracts.
This doesn’t limit the Feds. Also, a state can prohibit non-compete. Etc. Basically, the freedom to enter into a contract is not one of the four corndogs of freedom.
The law (OK, well, British law) does recognise that many terms can be Unfair especially when one of the parties is an individual, and especially when it relates to employment. They can nullify them on that basis.
This sort of ridiculous “criticism” is why I have a hard time taking libertarians seriously.
You're invoking a common "libertarian" trope, so I'm going to address that larger topic. Right-fundamentalist (ie axiomatic) "libertarianism" is fallacious. Logically, by asserting an unlimited "right" to contract, one can straightforwardly reframe any totalitarian state as merely being contracts between the state and its citizens/subjects/victims. And simply renaming things clearly does not make for a society that respects individual liberty!
The only sensible way to approach libertarianism is to qualitatively evaluate individual liberty. And being prohibited from speaking 8 years after the fact, especially when there is a compelling public interest, is in no way equitable. If they want her continued silence, they should have to buy that on the order of year to year.
So allowing someone to sign themselves into slavery should be "legal" because it's "impinging on someone's right to enter contracts"? I get that some people balk at "morally reprehensible" as some sort of slippery slope, but c'mon we as individuals have to function somewhat coherently. As a social species reliant on some form of social cohesion (how much oil did you refine this morning?) we have to have some guidelines.