Author of "Careless People" banned from saying anything negative about Meta

https://www.thetimes.com/uk/technology-uk/article/sarah-wynn-williams-careless-people-meta-nrffdfpmf

Meta stole Sarah Wynn-Williams’s voice. It couldn’t stop her exposé

The author was gagged by the firm after her book, Careless People, alleged sex harassment and censorship. Its actions prove her point, says her publisher

The Sunday Times

My understanding is that as part of a severance package she received in 2017 she agreed to some kind of "non-disparagement" clause. She then went on to write a book disparaging the company. The arbitrator didn't rule on the disparagement itself or if anything was true or false. Only ruled that she had to abide by the contract she signed.

It sounds like an interesting book, and I'll add it to the list. But it also sounds like she agreed to this in exchange for a lump-sum severance payment, and then broke the contract anyway. I'm not sure if this is really that principled of a thing. She sought-out and accepted a lot of money for this agreement.

It should not be legal to enforce this kind of thing 9 years after a person leaves your company. I get that it currently is legal, but have some principles. Just because this is legal doesn't mean it isn't morally reprehensible, and its legality should be challenged.
It should not be legal to enforce full stop. If you don't want to be disparaged, make your conduct worthy of not being disparaged. When you're being lied about, sue for defamation; "non-disparagement clauses" are redundant at best, an attack on free speech at worst.