I believe some people in the organization had resistance to change. A change in culture isn’t easy and can do more harm than good if not implemented properly.
Besides communication, the challenge is that the change process is not clear. If the process of change is not known or clear to people, they would be anxious and have questions in their minds. They may question their ability to adapt and belong, it may bring insecurity of how they fit in, do they have the required skills, whether will it increase their workload, etc.