If you pass the persuade rolls she tells you the letters just started appearing one day warning her of the immitent goblin threat and how the grove was bound to fall sooner or later, so she took the deal out of desperation to protect her own. To me it seemed like yet another branch of the Absolute wanting the druid circle out of the picture one way or the other. It's true however she just comes off as a psychotic maniac if you fail your persuades.
It's going to be a real shocker when we find out everyone we have ever met is secretly working for the Absolute. Isn't it more likely Olodan is just doing what Shadow Druids are apparently known for and is thus working independently? If not then there were two conflicting plans operating at the same time on the Absolute's part.