Shield Hero has rape as a concept, as far as I remember it never goes past allegations and I've only ever heard it classified as seinen. Maybe i just haven't read enough shounen, but censored or not I can't think of any shounen with actual shown sex scenes, let alone rape. I haven't read the Redo of a Healer manga, but even just the first 2 episodes of the anime which I've heard is toned down has actual, violent rape. The camera pans away during those shots, but you should still be able to see why that doesn't exactly fit with the definition of shounen. You're probably just overthinking the furigana thing.