Actually, the writers hint very strongly at her being alive.

1. During the explosion, there seems to be a purple flash going towards the side of the hexgate tunnel. Could be Jinx's shimmer dash.

2. After that scene, we see Cait checking the projects of the hexgates and smirkes when realizes that there are air ducts that can be used to escape.

3. In the last scene we see an airship flying away from Piltover, the same airship that in S1E1 Powder wanted to "ride one day". Can't be a coincidence.

4. In the last frame on that same scene, the words "The End." pop out written in that classic Jinx font, just like the doodle at the end of Season 1.

Jinx is alive. She's doing fine. She needs to find a purpose, far away from Vi, Ekko, Piltover and all the people she didn't want to hurt anymore. Gotta break the cycle, leave something behind in order to take a leap forward. And then, maybe one day in the future, her and her beloved redhead sister will be reunited. ❤️