I think that's true for the stage production, less so for the movie. This movie isn't meant to be, and never was intended to be, a perfect replica of the stage show - what would be the point in that? It's a new adaptation, and a lot mroe can be done acting-wise on film than can be done on stage in terms of detailing, so if that's at the expense of big belting singing, then that's fine by me. As long as they're all in tune and the tone of their voices don't grate!
Yes I think a lot of the die hard Les Miz musical fans seem to have forgotten that the stage production itself is also based on Hugo's novel.
The movie itself sacrifices the vocals for the acting, which in turn better portrays and in my opinion, closer to Hugo's dark themes in the novel.
Anne's version of I Dreamed A Dream to me is the first time that the song has accurately portrayed Fantine's tragedy and anguish the way Hugo's novel meant it. All the songbirds from the stage version have always sung it with a dash of hope, which was not accurate at all.