Another baptism of nen unlocks it again.
I thought about what exactly happened with Gon and most likely if he gets gently baptised or hit with nen he will die. I can't read japanese, but I'm certain that the way Killua asked Nanika to heal Gon is relevant to all of this. Togashi may have purposefully wrote a line that leaves a leeway for Nanika's interpretation, unnoticable for translators back then, but playing out when looked back in the light of new revelations. Like "Ai". Nanika is not a human, it's friendly to Killua, but who knows just how straight it understood Killua's plea. The result may be simply healing, taking off the curse(what exactly groups into "curse"?) and recovering aura presence in the body, perhaps it's production (depending on how it acts in normal people, but this is a bit too overthinking), without lifting the restriction. Killua understood that Gon did a sacrifice (a contract), but did he know that there was also a restriction if Gon did one? Not simply sacrificing with big return, that gets fixed with giving back what he threw away. Putting a lock on nen use as an underlying. A bit of exposition is needed, else I can't put the semantics straight.
Gon sacrifices everything he would have in the future to gain his top condition (or simply up to the point of thrashing Pitou like an ant) and in return doesn't care for what comes next after the beating. Pitou thinks that this power can only obtained through sacrifice and never being able to use nen again is also the price, I see this as a hint for us, line becoming relevant now. Gon does his deed (and most likely understands what is going on before losing his arm), and to overpress Pitou's nen gives her Zero, with his own brand of "merciful scream of love". All the aura he has is depleted, he literally has no life force in his body now (Now what's interesting is what would've happened if Gon didn't do this. Would he start reverting back instantly while aura is seeping away at tremendous pace since target is done and the contract must be finished? Or would he be Gon-san until aura runs out at it's normal pace since he sacrificed all for this power but he still didn't use it all?). He becomes just like Netero, wringing himself out completely. But the trick is in the restriction. Not only is he like this, he also has no way of replenishing aura, his life force. He agreed to never use nen again and so after emptying the tanks he can't produce new aura. And most likely if someone had the hatsu of aura transfer Gon would have no way to use it, his body would not get hold of it. All he has to do now is die.
Back to the statement. So after being fully healed, and getting his aura replenished he becomes just like he was before Wing hit him. With one nuance - he still can't use nen. Yes, being refilled by Nanika contradicts my words about aura transfer hatsu. Write it down to Ai magic. Possibly being healed includes refilling and bringing Gon back to ordinary layman, or else he is not going to live, he would wither again. But aura is sealed, and seeps and generates at normal human rate. But if Gon gets baptised again, he won't be able to stop aura from flowing out, since it is one of nen using masteries, something he can't do now.
So Gon right now is very vulnerable and has a great reason to contact Killua or someone else who would point him to doctor Leorio and DC explorers and ask for help.
Or maybe it is all much easier and he is simply unawakened, without any curses and restrictions.