The boxes you listed are associated with page objects. PyPDF2 allows you to access and modify the coordinates for these boxes.
You're correct that bounding boxes are unrelated; a page may have none or many bounding boxes. I believe each bbox represents a region for a graphic, font, etc., rather than a whole page.
To answer your question, PyPDF2 does not currently provide access to the coordinates for bounding boxes. It is something that should be considered, though.
pyPdf and, by extension, PyPDF2, don't focus on specific content extraction as much as they do page manipulation. But this is a concept we will look into developing!