That is true, but you have to look at this a lot more "holistically": The processes in the PMBOK Guide are not always linear. While the PMBOK Guide shows them as separate and distinct, it also notes that "in practice, they overlap and interact in ways that cannot be completely detailed". This is one of those situations.
A simple example: A project starts with people. Someone has an idea and that someone becomes the first stakeholder. You as the PM work with this stakeholder to develop the charter. As part of the charter you develop an initial set of requirements and based on these requirements you will have an initial list of stakeholders. As the project progresses you have to work with these stakeholders and their input will probably add new requirements to the project, which may help you uncover new stakeholders. These new stakeholders will once again have their own agenda and requirements, which will once again lead you to the discovery of yet more stakeholders and more requirements.
OK... maybe I'm starting to go overboard on the above, example, but you get the idea...
This is a circular and not a linear process that begins with the people involved, who will tell you what their needs/requirements are. Or if you prefer you can view these processes even as parallel: You do both at the same time -- the people influencing the requirements and the requirements influencing the people.
I am a little confused about Stakeholder Management Plan being an inputs to Collect Requirements but it isn't developed until Plan Stakeholder Management Plan. Do you have any idea by what alchemy this is achieved?