In internet, in most places I've seen "draft" as being something that is not yet published. For example in a lot of blogging software like WordPress, you can save your post and it will be "Draft", but only will be visible to others when you publish, so it's not thrown away in most contexts that I know it being used in the Internet.
Isn't it the same connotation here? The work is shared with your collaborators, but not yet "published" to the master branch or to customers or wherever?
