The whole issue of "if you have nothing to hide then you wouldn't mind the government looking into x" is a question of basic human rights. It's a question of whether or not the government has the right to invade your privacy even when there is no suspicion of wrongdoing. In a society that believes in the "nothing to hide" principle, citizens have no choices. They have no rights to privacy. They are trapped.

The "if you have nothing disparaging to say, don't worry about it" is a question of making a choice. If you choose to be able to disparage your employer in the future, don't take the severance. It would be your choice. If you choose to be careful of what you say, then take the money.

Monopoly affects whether or not you have choices in a society. The government is a monopoly, a monopoly that has the right to physically force you into compliance. Because of that simple fact, everything the government does or is allowed to do requires much greater scrutiny.

Maybe you don't have anything disparaging to say now.

Maybe it comes out that your ex-employer was engaged in fraud. When you hear the news on social media you say "wow, Joe in accounting always did strike me as funny." You didn't mean it as disparaging. But the company does.