I was just curious about why the prequel to Celestia hasn't been removed from the game since you are given the Celestian key by the headmaster when you defeat Malestaire now. If I remember correctly, you got the key after the prequel - from the storm school professor although I could be wrong - but now this prequel quest with the storm professor makes no sense since the headmaster gives you the key after Dragonspyre. Just curious.
It is a very difficult dungeon at that level. Making it optional was part of the nerfing they did to make the second arc more accessible to the average player. It was one of the first cheating dungeons and turned away many players from continuing. Just like making Malistaire in Dragonspyre much weaker and more easily beatable.