Disposable absorbent articles having multiple absorbent core components including replaceable components

A disposable absorbent article adapted to be worn about a lower torso of a human body, comprising:

• a chassis forming a waist opening and a pair of leg openings and having a topsheet and a backsheet which extend to at least a first of longitudinally opposing first and second waist end edges, longitudinally opposing first and second waist regions adjacent to the respective waist end edges, and a crotch region longitudinally intermediate of the waist regions;
• and
• a non-removable absorbent core component disposed in the crotch region;
• wherein the chassis forms an openable chassis pocket extending from the first waist region into and ending in the crotch region, and disposed between the topsheet and the backsheet and beneath at least a portion of the non-removable absorbent core component, and adapted to receive an absorbent insert;
• wherein the openable chassis pocket has an openable end with an opening formed by a separation of the topsheet and the backsheet along said first waist end edge, and bounded at least in part by first and second elastically extensible waistband portions disposed in a layered configuration in the first waist region, the first and second waistband portions comprising respective first and second independently, elastically extensible elements such that the second elastically extensible waistband portion may be extended for access into the openable chassis pocket without extending the first elastically extensible waistband portion;
• and
• wherein the openable end is narrower along a lateral direction than the first waist region.