Oh those girls actually weren't forgotten about. I merely forgot that they were forgotten about.
As for me, I kinda realized what was happening to the royal guard and king the moment Youpi bled. But I am also familiar with the aftermath of nuclear weapons (though later this episode they did imply it pretty clearly, but I guess it might be hard to think of if you're not very familiar with the subject matter).
I know you didn't talk about this yet, but I'm assuming at this point you've at least finished this arc, if not the rest of the anime already.