The article is quite clear on what the issue is. Meta needs explicit consent to do this kind of targeting. With consent, there is no issue. The tracking itself is not illegal, but doing it without consent is illegal.
I get all the hesitancy in the comments here about the freedom of an adult to have a cigarette. However, smoking is a case where; if you're having a smoke at the same bus stop as me, I am inhaling that crap too.