I've heard there is a mod that does it, but I've never been able to find it. That said, claiming that Bethesda couldn't do it because modders can't when using the very, very limited tools that Bethesda has provided to them is ludicrous.
And as I've mentioned before (again, in this thread), this has nothing to do with the engine. At all.
You're missing the fact that these are all things that deal with the character's arms... which we can already see and use without any animations for any of these.
Maybe I'm not making myself clear in my previous comment, so I'll say these:
The developer definitely have ability and capability to implement this feature. But it's a HASSLE. Doing that (in my assumption) will involve extensive tweaking or even rewriting of the game engine if the engine didn't support it to begin with. If the development has already started, the developer already planned what feature that need to be add during design phase. The developer won't be rewarded for the hassle and in many case adding this kind of modification to a complex system like a video game may cause EXTRA bug/glitch. Which is more hassle than it worth. So (my assumption again) the developer will only add gimmicky feature than cant be easily added via player's mod. Not because they don't have ability to do that but because they have no reason for it.
And no. Simply changing camera position generally will only make very glitchy first person view experience. That's why you have difficulties in finding the so-called mod. Even if such mod exist it doesn't mean a squat because Beth's using a new engine we don't know a squat about.
I'm using assumption here because we have no knowledge at all about Beth's new engine for Skyrim or the development process. Unlike some people in this forum I don't regard my assumption as facts.