By taking away the private que for Siege giving credit for the quest this may turn this into a dead quest that no one does now. Getting 40 people to que up for the Siege will be very rare since people don't PvP in this game that much. As an Alliance we used this event to get people into PvP and they got a reward for trying out something they did not want to do. Now it won't be something people are going to want to try. If this event has no one doing it I hope you will reconsider this change and make it fun again.
I will be looking for other alliances that want to set up siege days and try to run these but that's a lot of people that need to join to pull it off now.