Well we Unit X are conquering territories now, so it will be easy for us to attack Stormwind on daily basis which we usually do. Also, it makes our route easier to pass through Duskwood, Stv, Kara, fagshire, elwyn, etc.
Soon we will make our new horde players level at those areas, which goes without saying that we don't wanna see any more ally players leveling there. A border patrol security with hordes guarding those bridges will be in place soon, so any alliance player who tries to trespass those places will be killed on sight.
PS. RED = DEAD