This makes total sense as a sort of exception to some the rules and advice early in the thread. I would imagine as a war novel, it's a fairly ensemble piece. Unless you're killing off the entire platoon and starting with all new characters, (which sounds like a bad idea, but what do I know?) you'll have at least some characters left to carry the reader through the transition. You might even be able to pull off having the reader grieve along with the rest of the team, as much grieving as time allows for in war, anyway.
Professional writers create memorable characters all the time. Look at how many Agatha Christie invented. That's kind of our job. Making characters that people care about and remember.
Tried a couple of her books and nothing resonated or stayed with me. There is one thing about Christie I feel attracted to. I'd read rather biographies about her than her books. From certain details on her biography, I can picture a quite interesting potential character for a piece of fiction. Well, taken as something everybody can learn to do it's more about writing books, just that. When done for a living, books that sell. Something not all of us can do (and I include myself here) is the ability to keep learning until the point of reaching our fullest potential. Even then, after a whole lifetime, you might not be capable of creating a memorable character. But now we enter another different question, which is what a memorable character really means.
Sometimes the death of the MC is a literal representation of the abstract death of the self. In other words, it's an absolute representation of her metamorphosis. There are other ways to represent a change so dramatically, but death is used often for a good reason. It's clean, absolute, and carries deeply personal stakes.
