Considering the storyline changes from other information from the era, such as details of the xel'naga's "last days" gleaned from the Overmind and Tassadar's status as leader of the Expeditionary Force, Oong's status is probably non-canon.
↑Tassadar: "Zeratul, perhaps the time has come to tell our friends of the foe we face." "Zeratul: "Indeed. When I slew the Cerebrate on Char, I touched briefly with the essence of the Overmind. In that instant, my mind was filled with its thoughts, and I tell you now our worst fears have come true.
"The Zerg were indeed created by the ancient Xel'Naga, the same beings that empowered us in our infancy. But the Overmind grew beyond their constraints, and has at last come to finish the experiments they began so long ago." Tassadar: "So you see my friends, we fight not only to save Aiur, but all creation! If we fall to the Zerg then the Overmind will run rampant throughout the stars, consuming all sentience-all life. It is up to us to put an end to this madness, once and for all." StarCraft. Vivendi Games. Mission: Shadow Hunters (in English). 1998.
↑Underwood, Peter, Bill Roper, Chris Metzen and Jeffrey Vaughn. StarCraft (Manual). Irvine, Calif.: Blizzard Entertainment, 1998.