Why? GH is its own side quest world that doesn't connect storyline wise to Celestia-or the rest of the Spiral-unless you some how connect the dark insect guys to the ravens, but since the ravens are defeated it would seem pointless.
Yes they should, because Grizzleheim is set up to visit as you level your wizards through the other worlds, and it would be nice to have quests there for the level 50-60 wizards.
No, they shouldn't, because Celestia is a "lost world" that was only just re-discovered, and if the bears of Grizzleheim knew about it all along, that would not make sense.
Yes, they should, because I LOVE Grizzleheim and adding another set of quests there would be great fun.
No, they shouldn't because lots of people seem to hate Grizzleheim, and making them go back there would make those wizards unhappy.
Yes, they should, because there could be new higher level drops from the new bosses and people are getting tired of farming Ravens all the time.
No, they shouldn't, because ... I can't think of any more. I think they should.
