Does FB use SAML for their login flows? I know Google has several different options and SAML is available, but was unaware about FB. Maybe in one of their more enterprisey apps/services?
If you want to federated eg AAD with Gsuite, it'll be via SAML, but I don't know of any consumer service that's ever supported SAML. It's so weird the author used Twitter when they were one of the classic original Oauth creators.
My thoughts exactly! A lot of the "social" things are OAuth based, not SAML. I know Google has both, but when doing consumerish things via Google, that's also OAuth based (iirc).