Pretty much a given for the RTS games leading up to WoW. What is canon about them has basically been codified in the "Chronicle" series of reference books - everything else is basically resigned to non-canonicity until it is brought up again (if ever). I don't recall if the "Chronicle" entry covering WC3: TFT happens to mention the Shadow Orb or not, but I don't think it does.
"We're more of the love, blood, and rhetoric school. Well, we can do you blood and love without the rhetoric, and we can do you blood and rhetoric without the love, and we can do you all three concurrent or consecutive. But we can't give you love and rhetoric without the blood. Blood is compulsory. They're all blood, you see." ― Tom Stoppard, Rosencrantz and Guildenstern are Dead
Blizzard right now: "The what?"