The angels were all in the division of what once was the barrier that separated the two sides of the Universe. To be more specific, the division that passed through the Heavens. However, the barrier was no more, and they could see into the dsitance. The Heavens were whole again.
"Let's go!" Dalquiel spoke, and all the angels headed deeper into the long-lost part of the Heavens.
---
In the Underworld, things were quite similar. It's just that most Devils didn't seem to care much about the lost part of the Underworld that now was back.
Moloch looked on the other side and spread his Divine Sense. He easily found many Devils... who had no cultivation whatsoever. If not for their bloodlines, he would find it hard to believe they were Devils at all. "Why does senior Black Locust even care about those Devils from the other side?"