I mean really, not really.
Characters and the movement component have to also have the specific class.
The class definition itself takes care of the casting and instantiation.
You can replicate this by creating your own character class, and extending the character class.
You can extract the animinstance, and cast the animBP on begin play via c++.
You then Store the reference (the variable can be exposed to BP in the header file).
The result is a variable you can use as the “animation” in BP which is “apparently” without casting.
In reality the cast just happens via cpp which can easily solve soft references.
Not that that’s how the ladder thing does it too - but it’s how I’d do it… there’s only one main skeletal mesh. It’s easy enough to query the “parent” for it and figure out what the animation BP is.
I’m all for doing components and animations as you suggest - completely isolated, add it in, and it provides the functionality required.
There’s also a cost to components in terms of memory footprint.
I’m not sure how likely it is Epic will go this route.
However, creating a specific component with a low memory profile that directly does just this, is a superb idea.
They really should put their R&D onto it - IMHO fat chance.
They can’t even get .27 to run ok off the launcher 
Maybe we should just take this on as a community driven engine mod… something they will probably pipe back in with a pull eventually if they think it’s worth it…