I got completely fed up with their developer warnings and decided to get rid of the Facebook login feature. It was very rarely used anyway.
What puzzles me is that what else I might need to do, in addition to disabling it from the settings? The admin panel does not seem provide a report that would show which accounts have used the Facebook login method.
Just as an FYI, if you’re looking for some customer support you can message @team or email team@discourse.org and someone will be able to help you when their working week begins on Monday.
Though you may be able to find this info using a data explorer query.