Comment # 6 on bug 917014 from Ancor Gonzalez Sosa

Efstathios, are you sure you are not confusing the language settings of your
desktop (managed by your desktop and not altered by YaST) and the system-wide
settings?

It's actually a rather confusing difference that "grants" us some incorrect bug
reports once in a while. Let's say you installed the system in English, with
Gnome (same applies to any desktop environment) and created the user user1. So
the system-wide language (for new users, for example) is English and the Gnome
configuration for user1 is English.

If you then run YaST and choose Greek as locale, it will change the system wide
configuration, but the Gnome configuration for user1 could still be English, so
that user would barely notice the change. That's by design, because each
individual user is free to define their language/keyboard settings.

Are you sure that's not the case here?