Yes, SOPRISM respects the GDPR norms and directives. SOPRISM uses the available aggregated and anonymized data thanks to the Facebook API, which means that no personal information is collected or processed in the audience analysis framework. The Belgian data protection authority performed an audit of the platform and has confirmed that SOPRISM does not process data which is considered to be sensitive.
For more information:  https://www.facebook.com/policy.php