Well, remember that they do cut out quite a bit, because they need to wrap up the plot nicely, right? So to do that, bits will be cut, and they usually manage to pull it off. But still, just because it's not confirmed yet... And things change
all the time, so...
He could still be in it.
Maybe they'll just end up with calling those roles "School Death Eaters" or something, so he wouldn't be named in the movie, but we would know who it is/meant to be.