Well, as a German I have a history with censored games (due to violence, mind you, because nudity here is no issue whatsoever. Full on display of boobs, nipples and vaginas or penises, no problem). In the past many games had dismemberment removed from the code (Fallout 1, 2, 3, New Vegas, several other games).
However, the context was very important to German authorities in regards of ""youth protection"", e.g. in Soldier of Fortune 2 they made all characters androids, even added a sentence in the intro that it's a parallel universe with androids, so flying metal limbs weren't an issue anymore (still 18+ game). Then it got a little bit more relaxed but some games had ragdoll physics or any other impact-related effects removed once the characters were dead. So this behaviour is not unknown to some gamers.
The rationale behind that is that any additional visible violence on a dead body is even more brutal and/or frowned upon than on a living thing. If a character is alive it could be self-defense, the goal of the game etc. but it CAN'T be the goal, or any necessity, to further damage a dead body, so it got removed.
It could be that some partners of the devs see it the same way and argue that violence in this setting and genre is inevitable so in the context of this specific game is OK, but there's no reason to do it do dead characters. This may be the line they don't want to have crossed.
On PC, I think mods will fix this.