Lucas himself announced the Blu ray release of I-VI at Celebration V in 2010.
Right, and as I remember it they got Hamill to show up at the 2011 convention to introduce the deleted scene from RotJ of Luke building his new lightsaber. I don’t remember now if that’s when they officially announced the release date for the blu-ray or if it was before/after.
The streaming versions of I-VI were actually released only a week or so before the 2015 convention.