Maybe "disempowerment" is a bit of a red herring, or a misleading problem to focus on. The reason we didn't spend more time on clarifying that is that we're just using it to gesture towards a different set of mechanisms that lead to extinction-like outcomes than usual. So even if you think our definition of empowerment is poor, or that empowerment isn't a great goal - that's kind of OK.
The thing we want to emphasize is that right now there are some mechanisms that steer our civilization towards keeping us alive, and free in some senses, that might stop operating. Though I take your point in the last paragraph that this might not change things much specifically regarding the implicitly empowering forces. We'll think about this one some more!