“Empty space” is usually thought of the as apparently unfilled space-time. If we imagine that the big bang blew into empty space, we are assuming a previous 3 dimensional space time. It’s what we know. We are not going to be able to imagine whatever reality with which we have no access or commonality. Should we not leave room for the ‘unknown’, and even a tiny space for the even less popular ‘unknowable’?
If an accessible dynamic (weather, electricity) is affected by tiny differences in one of many facets, the resolution of predictability would eventually find itself having to consider magic like quantum and other perhaps inaccessible forces.
But just because we can’t figure it out, should we call it chaos? Chaos is known to us. It’s like turmoil, we’ve all seen a form of it. Do we know the unknown good enough to give it a derogatory nickname? We don’t want to generate any semi-accessible yet understandable indignation over how steady the laws of physics are.