Do not force an EOL (End Of Life) of major branches, especially that of major software.
For example, there has been major changes between KDE3 and KDE4 and again between KDE4 and KDE Plasma 5. Similarly between Gnome 2 and Gnome 3, etc. Very often, distributions more or less 'forced' users to upgrade from one to the other, even before those big frameworks had achieved an adequate level of stability, leading to much discontent and probably unnecessary forking (e.g. KDE3 => Trinity).