It’s not difference in this situation.
Alliance *might be* forcefully raising the dead as vengeful ghosts to attack the Horde.
Horde raises the dead to attack the Alliance.
It’s pretty straight forward if it will ever be confirmed that the dead raised by the Horde during Battle for Lordaeron had souls and were forced into servitude and that the ghosts raised by the Alliance were brought back forcefully. At the moment there are a lot of ifs, but none of these “ifs” are connected to the Horde raising their own troops.