I think your getting the "what-about-ism" argument backwards. This isn't avoiding talking about Google by saying "What about Facebook". This is comparing the two to highlight it's point about Google, the subject of the article.
Maybe I have it wrong but what-about-ism isn't only about avoidance. It is also about drawing an equivalence saying - "Yes, X is bad but what about Y?" The idea being if everyone does it then X hasn't done anything wrong.
Noone is saying Facebook hasn't done anything wrong. We just don't want Google to get away with it.
Whataboutism would be if we were to suggest Facebook isn't that bad because Google does it too. But articles like this are trying to point out that both companies are doing bad things: We should be going after both of them.