Wouldn't it be better to run an additional train?
At the end of the night for something that might not even happen. The issue will only arise if the match goes into full overtime.
To do that GA have to keep three drivers, three guards and three trains in Ipswich just in case at a time of night when people have either gone home or units are heading to their various berthing points or Crown Point. Anything to try to run trains for this causes issues. They either just hold trains till they need to, in which case staff and normal passengers are just sat waiting with no idea when they might go. Or they could just mod all the last trains to leave at 2300 so everyone gets delayed anyway even if the football finishes on time.
GA (or any TOC) are not a personal service for the FA. If the FA want to schedule matches that might finish after public transport than thats a problem that need be sorted by the FA, not by a TOC. This attitude that everything needs to exist around football really gets to me.