So, I log into my discourse installation via facebook, and I noticed that after I updated my facebook primary e-mail address, this email is not updated in discourse. This is causing an issue as I no longer receive emails from discourse.
Are the permissions on your Facebook account set to share email?
Is the email field on your Discourse account editable?
Facebook doesn’t have to provide Discourse with your email address, your account permissions can prevent this. In those cases you are prompted to manually provide an email address at registration.
You can check your email at /users/USERNAME/preferences/email, substituting USERNAME obviously.
I think our behavior here is correct, you can always amend your email via the user prefs, we do not key on email alone, we have a unique id from facebook that ties your auth together.