Instead of having random pop-ups notifying you of the historical events taking place, Victoria 3 will have the Journal Mechanic. Players will be able to see the potential outcomes and act accordingly upon them before they happen.
Compared to Victoria 2 Paradox have shifted the focus of scripted content away from random event popups and towards the Journal system. Journal Entries fulfill a variety of narrative and mechanical purposes in Victoria 3 - they can be optional goals the player can pursue, imminent disasters, anchors for ongoing situations, and much more.
You can think of the Journal as items on the government’s agenda, situations that you can engage with, or not, to whatever extent best fits your goals and situation.
Inactive Journal Entries serve to announce potential goals you might want to pursue or disasters you might want to avoid, depending on what you’re aiming to do with your country. Many Journal Entries have an effect upon activation, usually, an event presenting the situation to the player both narratively and mechanically, and sometimes offering different approaches to the issue.
The Confederate Canada Journal Entry, for example, leads you as a colonial overlord down the path of consolidating your Canadian subjects into a single nation.
This is reflective of the developers' goals for historical content in Victoria 3. They say that they want to avoid arbitrary historical events that occur for specific countries even when they don’t make sense in relation to what’s happening in the game. While they also want to avoid writing content that only happens for particular state actors under hyper-specific conditions, making it all but invisible. So historical content should be both emergent and visible to the greatest extent possible.