Most change happens inadvertently. Some things, or more often than not many things, evolve and stop to be what they were in the beginning. Gradually, you change as well, and at some point you stop, look back, reflect, and realise that change has happened. It’s nobody’s fault (or merit), just the nature of things.
Some change happens because of an agent. That’s when a situation is no longer sustainable, and some person, or more often than not a group of people, decide to bring about change. At the beginning, it’s probably not very clear where they are going to land. But the intention is there, and eventually the context and its features are modified. Whether the agents are successful or not.
One way or the other, the people that are touched by the change rarely want to hear “this has happened”. They are often scared, they don’t know what’s going on, they see some of the fundamentals in their worldview shaken. And they want a forum where they can express all this and get some sort of reassurances. This process is part of the resistance to change, and it will happen, one way (in an organised, public way) or the other (in a dispersed, private way).
It’s the difference between communicating change and managing change.