Title says it all, Without the formation of the horde by the orcs, if the orcs never showed up, what do you think would have happened to Azeroth.
Would things be status quo, better, worse, or somewhere between all three choices. As much as people hate thrall would Azeroth have been able to defeat Deathwing without its "Green Jesus" as people like to put it.
Sorry if there's been other topics like this, couldn't find any