What is your point exactly? You keep repeating that Illidan was making an army, and nobody denies that. But what does it have to do with the original point that Horde and Alliance had reasons to attack him? Are you trying to say that both factions should sit idly and watch Illidan turn Maghar into fel orcs? You know, after years of fighting with fel orcs in first war, second war and in Ashenvale? Should Thrall just sit and watch his people being turned into mindless brutes to fuel Illidan's army and think "hmm let's see what he's going to use them for"? Should Alliance just let Illidan (who consumed demonic artifacts, almost turning into a demon, who teamed up with Naga, blood elves and caused huge earthquakes in Azeroth) keep making a demonic army and hope they will not try to burn Stormwind for the second time?
Call it as you wish. The official version during TBC was that Illidan has gone mad and betrayed Akama, started training demon hunters, corrupted blood elves with felenergies and created demonic army.There is no retcon. Its called filling in the blanks.
Now Blizz came up with a redemption story about how Illidan wasn't crazy after all.
And now we have a bunch of people going with "oh, we attacked Illidan, we bastards, but he was good"