I mean, I can already do that in Timberborn, so maybe not the most impressive example. The later example about basements collapsing due to the walls turning to mud? That sounds quite a bit more interesting, but it also makes me wonder how much they are overpromising here because that sounds wildly ambitious and unrealistic based on my current understanding of technology. I have no idea how they expect to be able to pull this off at anything resembling a reasonable simulation rate and fidelity without exactly the kind of pre-simulated, "you can do it here but not over there" situation he describes becoming inevitable.
It sounds really implausible. I wish them luck, because it would be really cool to see, but I'm not going to get too excited unless and until I can actually see the final result.