As in actual world, providing context to physics of things, providing logical association/evaluation, and so go on. It is basically something that supposed to help LLM get closer to understanding the "world" rather than just spewing out whatever the training dataset give it. It does have a direct implication for technical writing, because with stronger understanding of the things you wanted to write about in technical writing, LLM with World Model would basically auto-fill that.
This is something that the researchers are pretty much all hand on deck working on to create.