Maybe to try a different spin on this, accepting that checking at the beginning of a journey is best for the airline and prevents may downstream issues, could not -- in this type of case -- for there to be away -- on an exception basis -- for the child to have travel to the meeting point (ORD) and then continued on with parent and passport?

Earlier I think there was a suggestion of only issuing a BP for the ANC-ORD leg and not issuing additionally BP. Hence requiring further BPs to be issued only after passports / travel documents where are properly presented.

Why could not this alternative been allowed on an exception?

Is this the case of a rigid inflexible system?
Is this a case of lack of employee empowerment?
Is this a case of lack of employee / company interested in customer service?
Os this the partial release of BPs just not possible (IME I believe it is but ..)