The default OIDC handler ignores updates to user emails

[squahtx]

I can add some detail about this. My issue is slighty different but I think not enough to open a new one:

User information from OIDC is only fetch at the initial user creation and never again. If you add the email_template to the user_mapping_provider later existing users will not be updated. If a users email changes this change is never reflected. If you set the log level of the sso and oidc handler and log in with existing and new accounts it's clearly visible that user information is only fetched and successfully stored with the initial user creation.

Originally posted by @loelkes in #12605 (comment)

---

Note that user emails are stored in user_threepids, with medium='email'.

[clokep]

I think this is essentially a duplicate of #5763.