On Saturday May 19th Facebook published a one-page advertisement in the famous FAZ (Frankfurter Allgemeine Zeitung) newspaper (Germany) regarding the GDPR which is to become effective on May 25th 2018.
Facebook also mentioned new features regarding the access to personal data (access, download, deletion).
There appears to be no mention regarding the portability principle.
Facebook seems to invest a lot in public relations and communication following the Facebook / Cambridge Analytica data scandal. They are playing for high stakes.