[His expression isn't so much unimpressed as it is... unconvinced, perhaps. He reaches out and claps Kirishima on the shoulder, shaking his head.]

Not loss in the sense that he's deceased, but he's still lost to you, and that warrants a period of grievance. I'm certainly not one to harp, as I handled the loss of my brother's heroic ability very poorly, but you have to be willing to accept it for what it is in order to process it. He wouldn't want you to be torn up about it, but I also doubt he'd have wanted you to bottle and ignore your feelings about it.