Why is the Armv7-M CPU shown here and not the Processor core?

I don't know, but might simply down to the person who wrote the TRM vs created the diagrams.  The definitions and distinctions between processor, core and CPU seem to vary in time/company/setting.  That's one reason why generally the architecture specifications use the term "Processing Element" - to avoid any historical confusion around the more common terms.

I don't know, but might simply down to the person who wrote the TRM vs created the diagrams.  The definitions and distinctions between processor, core and CPU seem to vary in time/company/setting.  That's one reason why generally the architecture specifications use the term "Processing Element" - to avoid any historical confusion around the more common terms.