When activated it will rip the leather stitching wide open on the door card. You can't simply buy new inserts, it's the whole panel/ card.
You can separate the leather panel out, but it requires several feet of heat welded plastic to be split. They could then in theory be recovered and bonded back together.
IMHO - not an economic proposition.
EDIT - the airbag deploys along the stitching line, roughly between the door pull and the airbag badge (that actually just hides a door fixing)