If you were not aware, Michel Koch is one of the two directors of the first game.
An easy way to make sure Kate stays alive is letting Chloe die. Easy fix, hehe.
On a more serious note, while that theory is comforting to hear, I think the beauty of these games and the first Life is Strange in particular is the incredible amount of loose ends it leaves. It’s up to you to decide who manage to save themselves or not, that’s a different story that the game won’t tell you.
This might contradict LIS2. Because in the Bae ending, David says everyone in the town died.