Not that it should be necessary, notion should not be violating you're privacy by default, but at least uBlock/uMatrix block the entire fullstory domain by default.
In the EU they are by law. In reality not all websites disclose all services they share data with though. And all users click accept in the cookie pop-up anyway.
Have you seen those pop ups with a button to consent to cookies and a link to a privacy page where usage of 3rd party services like Fullstory has to be disclosed? That's your opt-in.