Question:

Is it possible to translate the Login Message based on the user's profile language settings?

Answer:

It is possible to translate the login message using the user interface (UI). The setting is required for a user who needs access to add the localized message. However, it is not possible to translate the login message using the Translation Workbench for all languages at once. It can only be done on a language-by-language basis using the UI.

Once it is translated, the localized message displays based on the user language.

Check the following: 

1. Navigate to: Admin --> Configuration --> Login Messages.
2. The Vault must have multilingual labels enabled ()
   
   
   
   
3. The user needs to have permission to modify localized labels (modified in the user profile).
   
   
   
   
4. Navigate to: Admin --> Configuration --> Login Message.
5. The user should see this in the login message. ():
   
   
   
   

Related Documentation:

Vault Help Documentation: Configuring Login Messages