While this is consistent with other research on the matter, it seems to focus on emotional processing.

I wonder to what extent this effect is in part a simple byproduct of the brain performing information triage and flagging things as "for follow-up" or "resolved". It stands to reason there's a strong overlap between "everyone is happy" and "nothing here needs your attention", as well as "there's a problem" and "action needs to be taken".

Music theory has explored how note progressions that feel "unresolved" are attention grabbing whereas chord progressions that resolve to the root feel plain and complete.

Aye.

If you've ever looked into modern prosthetics (which you should because they're neat), there is a lot of cool new tech that uses nerve sensing to detect signals and map them onto responses. IE a person thinks about moving their arm, the sensors read nerve signals in the amputated limb, and can map out "this signal pattern = this movement pattern". The person practices and over time is able to train their body to behave in concert such that the signals they send out are consistent and predictable. Neuroplasticity is just the process by which the brain maps those logic paths.

From the article, it would appear that these patients with ADHD, employed coping mechanisms, and over time those mechanisms facilitated neural remapping such that their "remission" is really just them retraining their brains to circumnavigate the problematic responses with the "corrected" responses to the point they didn't need to deliberately employ those mechanisms.

I'm not a neurologist but I am good friends with some. As I understand, the difference is that coping mechanisms are superficial whereas neuroplasticity is ingrained.

That is to say it's outwardly the same thing, but employing coping strategies over time results in rewiring neural pathways to the point they're not "coping" strategies so much as your brain perceiving it as the normal, correct response to that stimulus. The same mechanism as practice driving muscle memory.

Noted. Good clarification!

Perhaps I'm reading this incorrectly but... are they not just describing general neuroplasticity?

It sounds like what they observed was just neural pathways remapping as a result of deliberately repeated behaviour. This would be consistent with our existing understanding of how the brain can adapt to changes in input needs and sensory processing, no?