What puzzled me about selling to Disney was that Lucas has always been against Hollywood and anything coming out of the Los Angeles Studio area. He had done business deals with Disney such as getting Star Wars rides into the Parks but when it came to filmmaking he was totally independent.
All of the prequels were financed by Lucasfilm and the toy merchandising deals. Lucas kept a tight reign on those budgets as well as McCallum which may account for those digital sets. He was paying for everything and the OT was the same way.
The white slavers remark, even though it was a snide joke, was from a viewpoint he shared for 30 years. He views all of the studios in hollywood as slavers of some kind. Not true artists like himself (or how he sees himself as still that 70s film radical).