From what I have read, the brain is only developing or maturing in specialized areas. For his age, judgement is an important maturing need. It is not like the brain is continuing to grow more neurons. The existing neurons are developing new skills.

As he brain settles down from this time of maturing, his symptoms should stabilize.

What are you looking for in another neuropsych assessment? It may show that he has regained some skills. Whether it does or doesn't, there is not much that can be done.

Does the neuropsych assessment include a tourettes diagnostic?

What other symptoms are manifesting at this time?