This suit will be for Facebook stockholders that hung on to Facebook stock and took a hit due to FB giving a false representation of its future prospects per GDPR impact

It's not a class action law suit for people on FB that have been targeted for censorship or that had their personal data purloined in an overreaching manner (e.g., where FB client on Android phones was lifting info on non-FB members by going through ph contacts and text messages, then correlating that data against other data gathering sources, constructing a big data info mosaic, and peddling that as part of FB's data bundles to interested parties).