A whistleblower is the type of person to refuse such an NDA, regardless of buy-off price. They would understand that if Boeing is willing to pay them 10 million or whatever, that the information they have, should they release it, prevent over 10 million dollars worth of damages to the public.

Maybe, but 10 million dollars is nothing to Boeing, and an awful lot for even an ethically driven person. Especially if they've been laid off and are in active lawsuits against a multi billion dollar corporation.

They can afford to stall as long as legally allowed, and the legal system is built to levy the scale in their favor. It's basically impossible for a person in this type of suit to have a normal life, and the corporations know that and try to exploit it as much as they can.

I just don't see someone like that committing suicide in a hotel parking lot out of state the day (two days?) before they are supposed to testify. That would go against everything they were doing up until that point.

Suicide isn't timely, nor is it a logic based decision. Unfortunately it's fairly common for people to kill themselves at times people (especially their loved ones) would not initially expect.