I don't like having deleted scenes added back into a movie... unless the movie really lacked something to begin with. (Like a character's motivation for a particular action, or the emotional response to something.)
I don't think BBM lacks anything. The cemetary scene looks poignant... but I think that the two closets convey Ennis's sense of loss, and I think that their power would be diminished by showing more.
I think this movie is a masterpiece, in part, because of what it doesn't show or doesn't say. Because it leaves so much up to the viewer. So while I want to see every little piece of footage that was shot, I don't want to see it within the movie. (And I really, really, really don't want to see an extended version become known as the "real" movie, as has happened with the Lord of the Rings movies.)
Commentary tracks, though... I would like those.