CFO transitions in large corporations like Costco are significant but typically well-planned to ensure stability. The appointment of Gary Millerchip, with his extensive background in retail and finance, is likely to be viewed positively. However, such transitions can bring uncertainty in the short term, potentially affecting stock performance. The continued involvement of Richard Galanti in an advisory role and as a board member until January 2025 provides a layer of continuity and stability, mitigating potential negative impacts.