The change was made in the 2008 Watchtower. It was not clearly understood by many and was addressed at subsequent conventions. It was then clarified in the 2010 WT. It has been adressed at conventions and assemblies again since, as well as further WTs. Nothing in the doctrine changed from 2008, they have just tried to be more explicit since they have no logical or scriptural backup for this crazy view.
It was new shite in 2008. Everything else since then has simply been attempts to polish the turd...
