Dragon Age has a few instances where the story gets retconned. The most famous example is one major character who can die in Origins, but is canonically alive in the sequels.
As for the mages, I don't know the exact details, but maybe it only applied to the circle in Ferelden. Kirkwall is separate from Ferelden, so you won't feel the changes there. Not only that, Alistair doesn't actually have any authority over the circle (the Chantry does), so he can make promises, but won't be able to keep them.
The epilogue slides also often get ignored. There's one possible outcome where Cullen loses his mind, kills a few mages, and is locked up. That outcome is not reflected in any playthrough of either DA2 or Inquisition.
@troubleclaws wrote:
Till now I dont see point of my import save!
It's true that the impact of save importing is often minimal. There are a few major differences here and there, though, especially in Inquisition.
Cullen going mad is explained away as a rumor, and IIRC if Alistair is king and mage independence was chosen as the boon, it gets referenced in a conversation where Alistair is told that the Ferelden monarchy has no such authority and is blamed for the Kirkwall mages' actions.
