Sony stated why they didn’t use the newly remastered mixes for the CD release that coincided with the digital collection. They said and I paraphrase “Younger generations grew up on the SE scores so we decided to use the SE mixes for the CD release” youtube.com/watch?v=YuH7uznb2bU. But now I guess they decided to release the original soundtracks for streaming. I think this is a sign of cool things to come bois
I think that the original versions of the movies are restored in 4K and will be released sometime this year. Possibly an announcement at Star Wars Celebration.