Meta already has literally have billions of people's personal profiles and browsing history.
I don't think screenshots of their SWE's IDEs is going to be useful for identifying internet users.
I do agree screenshots themselves are less useful for that.
1. Why use their employee's data to fingerprint input? They could do that to a billion+ of their users instead.
2. Input fingerprinting is multi-decades old science, there are already production products that do this.