Absolutely, I think (B) is quite a big concern for people. While it's nice to have a fuzzy AI match things _most_ of the time, it's absolutely critical the user can always go in and override and take control of the situation.
So for us, we very clearly distinguish "a user labelled this item" vs "we guessed it was this label".
Haha, I don't want to go too much off topic of this thread, but essentially we can analyze actual file contents, source and metadata to find patterns between file structures and associate them to user and "common" labels.
On top of that we try to get further accuracy by using user information to help us find the context. We call it a Personal System, a repo of knowledge and learned preferences heavily tailored around each individual user. We're just in beta now but definitely put your email down if you want to try it out eventually!
Hey guys, you should look at diamond.io, we're building something that is a tool to help you solve this problem and the problem of organizing information in general. Check us out!