A It’s possible that turning down the promotion hurt management’s opinion of you. When you reject a promotion, it raises red flags. You may cause management to look askance at you from here on in. After all, you’ve suddenly attached a stigma to yourself as someone who rejected what management probably viewed as a sensible, even enlightened promotion. You’ve also possibly jeopardized their perception of you as a team player.
Request a meeting to clear the air. During the acquisition, ask to be included in meetings. Participate in the process and remind management of your value and insights.