Not only renaming, but re-bundling entities, moving layers, changing abstractions – refactoring is crucial during and immediately after development. As you implement your idea, you will inevitably find a better way to express it, and it's crucial to be able to re-do these things as many times as possible to reach the best possible result (if it's not a throwaway prototype, of course): no maintainer, including yourself a month later, will have a picture as full and clear as you right after finishing the first iteration.