"But note this doesn’t mean everything will be perfect. If the acquirer decides that you are no longer needed, they could keep your option agreement intact and terminate your employment. You wouldn’t get any further vesting unless you have single-trigger or double-trigger acceleration, and you’d be out of a job. It would be the same as if you’d been fired by your company before the acquisition."
Maybe I'm reading this incorrectly, but if you don't have single-trigger or double-trigger acceleration, the employer has all the leverage they need to renegotiate your (incentive) contract.