GP could still have died despite there being an Institute of War
I think the Bilgewater event truly was a step in the right direction, but this step could have been taken even if the league was still in tact. it would have resonated with the summoners more if we were still part of this world.
The Institute could then have levied MF certain repercussions for her actions of bringing Bilgewater into disarray. TF and Graves stories would then have progressed into confronting Rath together....