Mechanically speaking, Divergent Universe was an attempt at revamping the baseline Simulated Universe and make the weekly farming for ornament EQ easier.

In terms of Lore, each of the Simulated Universe updates contain big lore dumps on the general cosmology of the Star Rail universe. The Swarm Disaster patch told the story of the Swarm Disaster. The Gold and Gears told the story of the Anti Organic Wars. Both of these are major events in the ancient history of the HSR universe.

This lore isn't too relevant to the present day storyline. They're more to fill in the background setting.