Since T11917/rPa1025ca52e03 logged-out Users should get the global settings. But this only applies only for Installs with the config policy.allow-public=true.

In my install in the language set to german by global user setting and the config is set to policy.allow-public=false, but it does not translate the login mask. For testing I set policy.allow-public=true and the login was also translated.