You've characterized this as "impersonation" in order to exclude the possibility of parody, it's merely sophistry. This is a view of parody that falls apart when you look at actual parody. There have been many times I've been absentmindedly reading an article, been incredulous, and then realize it was from The Onion.
I have characterized it as impersonation because this is exactly what has been done in this case.
It's funny that you mention The Onion, because they are impersonating nobody since there is no legitimate news outlet named "The Onion". Their articles might mimick the writing style of legitimate ones, but they are not claiming to be CNN or Fox.
