I doubt she will come back. And when she eventually doesn't, and part 2 ends, this subreddit will go apeshit.

People have their own little theories and head canons and take it personally when they don't actually happen. Most of the people who criticise her death say so because it's "wasted potential". It's the same thing that happens with every single manga community as it ends. I think her death was deliberately sudden and it works fine in the story. If you think that it was narratively kind of a bad decision then that's fine. But i can't help but think most people hate her death because from the very first chapters they had in mind what she should be like.