It's not "it may have", it was inevitable. Support it or don't, it doesn't change that it was coming. Kirkwall set everything in motion and mages saw that they didn't have to be held ad treated the way that they have been for years. That's literally how Asunder starts. It's a build up.
It was what was coming?
The Circles were being contained, magic was being held in place.
The other circle that attempted to pull a kirkwall was entirely annulled. Stability and Order was being preserved, argue it as you wish, see it as you wish but until Fiona brought up her treason i saw nothing immediate coming right out of the woodwork that would magically upset the balance even more.
Like i said i don't support the reasoning she should be forgiven because she instigated something that perhaps could have occurred regardless.