The changes follow earlier deployments in a small number of countries and will apply to both new and existing accounts.
Under the updated model, accounts are placed into a teen-oriented experience unless the user confirms they are 18 or older. The change affects access to age-restricted spaces, content visibility, and certain communication features. The approach standardizes protections for younger users across all regions where the service operates.
Accounts using teen defaults will have tighter limits on direct communication. Messages from people outside a user’s friends list will be routed to a separate request inbox. Friend requests from unknown users will trigger warning prompts before a connection is accepted.
Källa: Face scans and ID checks are coming to Discord – Help Net Security

