Because the reason lies in switching from cultivating Light Energy to Abyssal Energy, the wings of the Abyss Angel had changed color. Whereas ordinary angels could still be seen in the outside world, angels like the Abyss Angel were impossible to find in any world other than the Abyss World.
With so many clues pointing to Zhou Tian for causing everything back in Heaven's world, the Light God King and his group choosing to flee upon discovering it is no surprise.
Though they're not in the Abyss World right now, the Light God King's team is not very large. So, based on the situation back then, after encountering Zhou Tian in the Heaven's world and recognizing his power, the Light God King and his group of Divine Kings clearly know that they're no match for Zhou Tian.
