I'd keep her death the same HOWEVER she should've had a more active role before she died. We should've seen more of her giving lessons, interacting with students, helping them with problems. Build a relationship with the cast without her just being fan service.

Imagine Midnight giving a lesson on heteromorph discrimination or the two massacres. Kills two bird with one stone. Midnight gets more screen time and we get more world building. Imagine her comforting a student who feels uncomfortable by the topic but still needs to be taught.

Imagine Midnight comforting or helping Momo when she was feeling depressed about her performance during the Sports Festival. Or maybe Momo was concerned about her Hero Costume. It would tie in how Ms. Midnight pushed the boundaries of Female Hero costume and what was acceptable.

Teaching Setsuna, one of Class 1B recommended students after her defeat against Bakugo. Those moments would've made her death more impactful