Well Sabre has this feature called stored fare and considering the scenario you mentioned. The TA has to call Sabre help desk and they guide you to ticket according to the stored fare (expired fare which when active allowed you to hold for 3 days but airlines has since then totally taken the fare off). The process used to be called Phase 4 ticketing, at least when I used to work for a consolidator TA. So it's possible but your TA have to call Sabre help desk or any other GDS's help desk, the one where the itinerary is put on hold.

In AA's case fare desk stores that fare for the EXP or any other agents you talk to

Hope I was able to explain the process :-)