Jagex are not developing content for the veterans, but new players.

[Wee Man]

What is Runescape 3?

Back in 2012 Jagex released a completely revamped combat system based on abilities and an action bar (similar to other mmos). This was wildely unpopular, at least with the PvP scene and in early 2013 they offered to release "Old School" servers using a back up from 2007. 

So the game that continued being updated from the 2007 back up is referred to as Old School Runescape (OSRS, 2007scape). The original game that continued from the evolution of combat update introduced some more new features in July of 2013 and was rebranded as "Runescape 3".