Ok, but what are the implications of that? If I own 0.001% of a private company—having decided to opt out during this process—am I at the mercy of that company in the future to determine how much they're willing to buy me out for?

How hard would it be to locate another 3rd party to buy my share? There's no longer an exchange to trade it on, and there might be all sorts of additional rules about how and who I can sell to.

Those are the questions each investor is asking themselves, and I assume that even with the large discount they're being offered, it's probably the better choice unless you hold a significant minority stake.