Please choose:
Present to the plan. It was board-approved. Your job is execution, not strategy. The numbers will surface the problem — let the results speak.
Raise your concerns with the regional VP first. Let her decide whether to surface it before you go to the CEO.
Request a separate agenda item for market intelligence. Frame it as new data, not a challenge to the strategy.
Say it directly in the first ten minutes: "Before we discuss Q2 progress, I need to give you an honest picture of this market. The assumptions in the plan do not match what I am seeing on the ground. I can show you what is achievable — but I need you to hear the real number first."