How do you deal with it, do you keep running this dungeon, even you know you have to run this dungeon anyway again because of the missing bosses, or do you just leave and requeue. Most time there is a reason.
In my opinion there should be an option to disallow started dungeons. Its simply a time waste to join as a tank in a running session where you can't finish the pledge, so the group inside dungeon is waiting for a tank for several minutes and the new tank just leaves immediately after joining the dungeon.
Today i had several running banished cells 2 dungeons, where the group is sitting at finalboss, waiting for a tank. I also immediately leave this group since there is no benefit to do this dungeon.
To solve this issue, just update the pledge quest to the latest state, if you enter a running dungeon, where crucial bosses are down already, so tanks has an intention to run this dungeon.