I'll be writing up a more detailed explanation and perhaps making a video for it, but in short:
Campaign worlds are huge. Many have far off kingdoms and all sorts of content the players aren't likely to interact with for many months of real world time. To keep your topics list from getting insanely cluttered, we opted to have a separation between what's currently relevant to the story and what's in the broader world.
The UI currently forces a binary choice between them (Story Almanac or World Almanac), but underneath I believe they are really all in one unified data set and differentiated by a simple flag. In the future we may change the presentation to show them in a combined view where you could toggle whether you want one, the other, or both. However, no promises in the short term.
