One of the MAIN purposes of a kick-off meeting is to:

Assigning and reviewing roles and responsibilities ensures that all project team members understand their specific tasks, authority, and accountability from the project's inception, which is crucial for effective project execution. This clarity prevents misunderstandings and promotes efficient teamwork, setting the foundation for successful project delivery.

While introductions may occur, the primary purpose is not merely the introduction of the project manager, but establishing the project's foundation and team structure.

The project definition document is typically finalized before the kick-off meeting; the meeting focuses on communicating and confirming its contents, not making major changes.

Ensuring team communication is an ongoing process and an outcome of a good kick-off, but not its singular main purpose, which is more about initial alignment and structure.