I don't think there'll be more of those, it was just to make you understand how fucked up things are and apparently it served its purpose since many people are talking about this. I also hate watching rape scenes, but at the end of the day it's fiction and just an element of the show to help you understand the overall situation.
I don't really have any issues with rape scenes as long as they are done "correctly". Rape is a very sensitive subject. It's just the way it was adapted here that was particularly fucked up. I went ahead and read the manga for this segment too, and while it is more graphic it did not feel out of place. They could have easily done something similar for the show with more censorship, but they chose to make it...a visual spectacle? I don't even understand what the goal was.
the thing is, it was portrayed in the pov from the rapist, it was made as a "fun" thing, because they were having fun raping her, and as you see it, you think "how the fuck is that fun?" and just makes the scene gross, that was intentional, this is the same thing as putting classic music in a warfare.
The author wanted to show that this is a fucked up world, where rape is portrayed as something fun and spectacular (from the perspective of the soldiers).
I have my problem as well with rape scenes, because I'm very sensitive when it comes to this topic. But I think this scene was important to give this show this different tone. Even though I disliked seeing it.