DLC = Downloadable Content. You download this, so it is DLC. Doesn't matter if they avoid using the word or something, or out it in mandatory patches . It's literally Downloadable Content (DLC)
That's what it stands for, but it isn't the way the word is used or defined by the gaming community. It is a different thing than a patch.
Not only the community, but the industry itself.
It's not just us "not knowing what DLC means", it's the standard definition the idustru came up with, like it or not.