In the last version of the Standard post delivery requirements showed up in 7.2 as part of determining requirements. The new 8.2 seems to have left it out since it is covered more fully in 8.5.5.
Post delivery activities could show up all over the quality management system. It could show up in 4.1 where you are determining strategic direction, 4.2 while determining needs and expectations of interested parties, 4.3 while determining your scope, 5.1 while determining Customer Focus, 6.1 while addressing Risks and Opportunities, 7.1 while addressing resource needs, 72 while addressing Competence, 8.1 while determining Operational Planning and Control, 8.2 while determining product or service requirements, 8.3 while addressing Design, 8.5 while addressing Production Controls (post delivery activities often need similar controls to production), 8.6 while considering how to inspect and approve post delivery activities, and 8.7 while considering how to control junk associated with post delivery activities (disposition of scrap generated during field repairs for example).
I'm sure that the list could go much deeper. 8.5.5 deals with how to handle post delivery activities if any should arise. It hardly seems necessary to mention it in all of the places it could arise.