Core Q&A Expanded Answer
The Blood-Oath of Draupnir changes both divine politics and the future. Odin's oath establishes peace between the Asgardian and Tuatha pantheons and their followers. Breanna's oath is to keep Loki from making Ragnarök inevitable, and she binds Loki into that same obligation. The result forestalls Ragnarök, ends the old Asgardian-Tuatha hostility, and opens the way for Norvegrs to join Breanna's northern coalition against Rome.