When it is needed, then yes
change management is critical. However, if you set your project teams correctly and provide appropriate feedback to the major stakeholders, you don't need change management. That is because everyone agreed to the requirements, and was keeping up to date on them. If a change in direction is needed, then it is opened as a different project.
The larger the project the less you want to change your direction. I have used change management only when a better answer that did not kill the timeline was found later in the process. That is when we did a change management and got everyone on bored with it.
Many times, scope creep happens because someone(s) didn't know the real requirements and when found out, they try to change their course back to them. Too little, too late.
