Also, Wikipedia is not infallible. I know someone on the CoD Black Ops Team, he states they're still using engines based on id Tech 3, and also that MW2 and MW1 appear to have been so as well. As well as WaW and earlier titles.
which wikipedia are you reading? COD2 is not on the list. also, your claiming the pcgamer article from sept 2005 is wrong? based on "knowing someone"? pcgamer interviewed the founders of IW regarding their abandonment of the quake engine in favor of their own in house engine.