I think it would be pretty gay to devote a whole chapter to Jairo's human life, basically saying "THIS GUY IS IMPORTANT REMEMBER HIM" only to have him killed off screen.
I mean the point of the chapter was alot like the Ace vs Blackbeard fight. Like the narrator said the Banaro battle would incite a later event, the Jairo chapter basically posed the question, If Gon and Jairo had met that day in the city, what would have changed? Which implies that Jairo will do something later, and that if he and Gon had met that day, that might have affected his action is some way.
So I mean if the answer to that question would have been "Jairo would have not died" or "Jairo would have died happy", even establishing him as a character would have been pretty fucking pointless.
From what I know, Jairo has already left the country.