I personally don't think Jinbe will die. IMO he serves or plays an important role in the themes of OP world. He is to be the ambassador who helps mend the gap between humans and fishmen. Having served for both Otohime and Fisher Tiger he has seen both perspectives in approaching the animosity between the two. He is the last remaining beacon of hope that both sides have. Add this to the fact that he is well respected, both parties referring to him as boss. It is this clout that will convince more fish-men to warm up to the idea of interacting with humans.
Another thing to consider is that he is the strongest fishman in the series. His knowledge, experience and strength will be needed in traversing NW which is more treacherous than GL. The quality of the enemies is going up and the SH crew growth should be able to match it. Come EOS I see SH having a collection of World's Best ot Worl's Strongest titles. Luffy PK title means he will be strongest man, Zoro will be world's best swordsman etc. Jinbe inclusion is going to add to this titles. If Oda wanted to kill Jinbe he would have done so the moment Akainu rammed his smoldering fist into his chest.