You’re def right the show couldn’t respectfully handle ww2, but what pisses me off is that they threw that flashback in at all. Without it, no one would really question why fu seemingly didn’t help because its a kids show set in an alt universe BUT the writers for some reason three that reference in so now fu seems like a huge jerk for running away 😐 they could’ve written so many other reasons why he had to leave Marianne without throwing in such antriggering and upsetting topic like that, the writers went way too far imo
The only reason I can think of that they went with that angle was because they wanted that “war-time dramatic romance” that’s not uncommon to see in movies. But ofc, in throwing in their favorite tropes and new ideas, they didn’t spend time actually fleshing out how their characters might be perceived.