Fortnite Chapter 2 Season 2 is set to be explosive, literally. The folks over at Epic Games have announced the reason behind the delay and that is that they are moving to the Unreal Engine Chaos Engine which brings large scale destruction to the franchise, kind of like the Battlefield games. Fortnite Chapter 2 will be launching on 20th February.
“Chaos physics engine” is an all encompassing term for those physics systems, not a specific set of things related to buildings and them falling apart. In general, tech demos exist to stretch limits of demonstration which is why that’s how they originally showed it off.
They could have just as similarly shown it off by showing trees getting knocked down or a pachinko machine. Just like how the current physics systems that affect character outfits can be turned off and on at will because they’re cosmetic, any implementation of this could just as easily be cosmetic and toned up and down rather than imply gameplay mechanics.