alt Hacker NewsI think the article is intentionally focused, if it were to mention every game that is related we'd be here for a while.
That said, this is a common thing in articles about e.g. video games - "I wish they mentioned X". I too wish that but at the same time, one needs limits.
MGS (and MGS2) are prominent enough, and directly relevant enough, and predate Shadow of the Colossus enough, that not mentioning them is a conspicuous omission, and not just something it would have been nice to add. In fact not mentioning them makes the article somewhat misleading, especially when at the same time it chooses to highlight Spec Ops: The Line.