Odd that it doesn’t mention Metal Gear Solid, which was casting doubt on the morality of the player character’s actions and painting boss fights as tragic affairs back in 1998, even though it does mention MGS love letter Spec Ops: The Line (and even though MGS is a media darling and probably significantly overdiscussed in general).
Slaying people is optional in MGS2 and higher, gameplay-wise. There’s not even a dilemma as long as you can handle hand-to-hand combat and a dart gun.
I 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.