Why are Project Management Plan Updates not an output of Plan Quality?

Harwinder

Why does Plan Quality not update other components of the Project Management Plan? In other words, why are Project Management Plan Updates not an output of Plan Quality?

What if we need to add new activities to the project for Quality management? What if we need additional budget for quality activities?

Ref: PMBOK Guide, 4th Edition, Figure 8.2, Page 192