During the quest when the player gets thrown into prison/the mine, they are supposed to either talk to Madanach and escape with him or kill him and escape alone. This completes the quest.
Since the Obscured Passage is now restored, the player can escape through that instead. This leaves the quest unfinished and no NPCs acknowledge that the player was in Cidhna Mine (which they do if you complete the quest).
So if the player wants to finish the quest, they have to find their way back into the mine somehow. No NPCs acknowledge that the player escaped temporarily. Not even the other prisoners.