WHBM : Thank you for raising this interesting conundrum.
I don't think there is an 'official' solution. If there is, I might be able to dig and find it for you amongst IATA regulations.
There is a facility which some airline ticketing systems have, allowing you to issue a ticket where a PNR does not exist, or to issue a ticket overriding the name on the PNR. This would be done routinely for standby tickets (staff) where sometimes no PNR exists, and in other situations for example where a FIM (flight interruption manifest) has been issued where a passenger journey has been interrupted. Also where a person is travelling on a passport in a former name but ticketed on a current name.
Airlines are faced with a number of such situations, for example when reservations are made for an expected and as yet unnamed child, or an adopted child.
There is a facility to change names in the systems, but again, this is problematic for many reasons, particularly when several airlines are involved.
I'm afraid you've opened a hornets' next here.