I think the structure of the paragraph is pretty clear (differentiating sentence, name A, explain A, name B, explain B, compare A and B), and the rest of the article matches my interpretation.

I would also think of regression to the mean (in this context) as an observable manifestation of "natural recovery" and not oppose them.

Yes, one could say that natural recovery is the mechanism by which regression to the mean works.

The chief thing I'm objecting to is the idea that the regression is in some way illusory or nonexistent. In the discussion of the NSLBP, for example, DC claims "none of the treatments work" when I think the result is the opposite, that "all of the treatments work." Now, DC and I agree on the right course of treatment (do nothing) for the same reason (why spend more to get the same effect as doing nothing?), but we disagree on the presentation. Instead of "treatment" vs "no treatment," both of which are equally ineffective, cast it as "natural recovery plus treatment" vs. "natural recovery alone," both of which are equally effective.

Here you might get into an object level vs. meta level debate. I argue that one should talk up doing nothing instead of talking down treatments that are no better than doing nothing, because it will be hard to convince the man on the street reasoning by post hoc ergo propter hoc that his attempts did not actually lead to recovery, but if convinced to try doing nothing then the same fallacy will, when doing nothing turns out to work, cause him to gain trust in doing nothing. One could respond that the important point is not that he get the object level question right, but that he avoid fallacious reasoning.