I haven't seen this, but as someone who's had DPDR for the better half of a decade, I don't think this article frames it 100% properly (which, to be fair, is harder with this than, say, general anxiety).

Yes, fear does come up during derealization experiences, but the difference is there's no grounded "you" experiencing this fear, more that the fear comes as "the experiencer" reconciling the reality one experiences with a new and disconcerting distance. This reads more like a profile of Pure-O OCD (they're comorbid so I got the two-for-one), where there is somewhat logical rumination about a specific fear.

I've never really had a DPDR experience where I was questioning my own free will. To me the external world at the time is best described as seeming aggressively real to the point it seems false, objects indistinct from others, bereft of any intent or memory. You feel like you've lost some foundational understanding of the world that has been instilled in you forever.