I don't use Scenes that much, but I do the Explode and Update steps all the time to check my assembly constraints. Any part that doesn't go back to it's intended position is missing a assembly constraint.
I've seen in Catia Assembly another Explode option: Edit> Move> Explode(apart of the one in Scenes.
I was wondering what would it be its use? All the components move away, when would one need that and waht for?........
if you import lots of parts into the assembly, they all pile up with their origins coincident. if they're drawn in origin, you have literally a pile. explode would spread those out so that you can apply assy-constraints (more) easily.