I think Disney/LF was trying to clear inventory of the 2011 versions. No different than how the 2019 DVDs also had the 2011 versions. It was just more simplified to have the 2019 versions pressed on standard BD for the saga set.
Can you clarify what the 2019 Blu-ray scans were? This is all so damn confusing. According to what’s spoken about on page 7 they make it sounds like the 2019 blu rays are the ones you want if you want the new scans, but I was under the impression that no new scans/color corrections happened to the movies until the 2020 releases