Let's say the case of the Bermuda Hoggies. It is an extinct team, but when revived it had some extra tricks up its sleeve. Apparently there is some hardcoding somewhere which was used when the team was active.
The team is used to set a Athletic Bilbao kind of system where the club forces you only to play your own nation's players. If the developer is checking code and sees the code for this specific team, they will say, the team is now extinct, but the code is still there. That code can be cleaned up. The team no longer has this special feature then and is just another extinct team.
We used this feature to our advantage, which is perfectly OK, but it was usable because someone didn't clean up the code and not because it was supposed to be usable like we did.