User blog comment:Martialmaniac/How will Gon regain his Nen?/@comment-26806332-20151016181454/@comment-5780397-20151017121027

Yes, he said that was the price he had to pay for the power to defeat Neferpitou, but he didn't really elaborate on that, he just said that Gon's aura was still there even though he could not access it and that he'd "gone back to normal".

I think there are some people (Nanika) or objects (Dark Continent) that could restore his powers, but, as you said, it is possible he might never get the chance to employ them. Mmh, I thought only now that maybe an exorcist would be able to lift the restriction... what the one from the Association could not do was removing the one that was killing Gon, but perhaps his inability to use aura is similar to Chrollo's.