Removing anything is mainly for the public image of the server. As it has been said a few times recently, it seems like the vanilla community would like to be lied too/held information from instead of having full transparency. The percentage on the progress bar can be seen as negative by newcomers - "85% and want to release in a month? pft, what a joke" etc. etc.
Removing things like Naxx and AQ (which won't be available at release anyway) will artificially push up the percentage thus improve server image.
Then again it is a bit too late now. Removing those raids - thus inflating the percentage - I think it would have a negative impact. Anyone who knows even a little bit about the progress bar could see things were removed, and percentage increased, and would probably scream bloody murder. So I say keep things as they are.