If I  read that explanation correctly it basically says that you no longer can override Locale settings.   You get what is defined by the locale.   If that is correct it is indeed a loss of configurability and it is the GNOME approach of restricting the options for the user.  

On Mar 10, 2015 11:03 AM, "Luigi Toscano" <luigi.toscano@tiscali.it> wrote:
On Tuesday 10 of March 2015 06:55:04 Gerald B. Cox wrote:
> Done.   Thanks for taking the time to report this to the list.   I'm not
> using Plasma5 but display my date as Day Month Year.  Hopefully they'll fix
> this in short order.   Configurability is one of KDE's strengths.   It
> shouldn't be GNOMEified.


Please note that his has nothing to do with GNOME or lack of configurability.
Instead of using the custom KLocale, the needed functionalities are now in Qt
and its QLocale class. So the system locale is used, instead of duplicating
the pieces for locale change. See for example:
http://vizzzion.org/blog/2014/05/locale-changes-in-plasma-next/

Ciao
--
Luigi