If the Project Management Plan integrates and consolidates all these other subsidiary plans as recommended by the PMBOK, then why not should it yet be an input to those Plans?....
Lets constructively debate/discuss and challenge this theory by the following:
1. How would the integration be if the subsidiary plan were strictly inputs to the Project Management Plan?
2. That instead be the Project Charter that becomes the Input into the Plans processes
All the other processes of engaging the Project management plan for effecting changes or updates remains the same, despite the change of theory.
With this one is trying to challenge some issues of logic within the profession.