So i'm a little delusional since arcane ended so i have some theories about what happened with jinx
The first one is where she actually died and this theory has a little sense because of cait's expression
if you see very close this scene you can imagine "oh cait is smiling because she knows jinx is alive” but the thing is that she starts to smile after she hears vi humming, she probably reacts this way because she didn’t actually ever got an opportunity to see vi so relaxed.
honestly this is my least favorite of all of the theories just because it brakes my heart to accept that jinx is actually dead
The second theory has two endings that might be possible, the first one is that jinx is alive but she left without nobody noticing, there is a lot of proof about this theory, the first one is that if you see very closely in the explosion scene you can see the little pink flash jinx uses when she runs, the second proof is that in ep1 S1 powder says "one day i'm gonna fly one of those” or something like that, so she probably escaped from piltover in one the airships and left vi, the third proof is that when jinx starts to hallucinate with silco, silco said "you must leave to stop the cycle” so probably jinx listened and she left vi.
The second ending of this theory is that she is still alive, but she didn’t left vi and she stayed.
Honestly the second one is one of my favorites because finally vi and jinx can be in peace, unfortunately not together but at least they are both in peace now.
If that theory ends up being correct i would love to see a mini series about jinx, or some comics at least.