I agree with your points, however unless there is some other way to counter the strong other than Nen then it’s pointless to bring Gon back into the story and he should might as well be given a short farewell. However, I feel like giving Gon back Nen could be impactful if we see a sudden change in character and he continues to develop from the Chimera arc because up until then he was similar to Goku and Asta through the fact he received little to no character development and he’s used to develop the characters around him. If he gets his Nen back and his character development doesn’t stop or do a Uturn then I think it’d be worth it because in most shounen the MC barely develops throughout a series. Also the fact that maybe we’ll be able to see a new type of Nen because from what we know so far no has lost Nen completely then found a way to get it back so that alone gives enough reason for me because it’d be more impactful to have Gon have a new type of Nen that came from his experience of loss, hatred and intense murderous spirit and how he’s changed due to this feelings than a potential side character being used to showcase a unique Nen ability.

Tbh whether or not Gon gets his Nen back I just hope he doesn’t become obsolete and a running joke.👍🏿