What is the latest reasoning on why they haven’t been released already? Waiting on the purchase of Fox to be finalized? Waiting until after IX?
It’s probably several things.
The pending buyout of 20th Century Fox would seem to be the biggest factor. They own ANH in perpetuity and the rights to Empire, Jedi, and the prequels don’t revert to Lucasfilm until next year. Until all the i’s are dotted and the t’s crossed, Disney wouldn’t want to be involved with a release they’d need to share profits on with another studio.
4k is the other big reason. Even if Disney had the distribution rights, they’d probably have waited until this year at the earliest to do any new physical release so they can debut I-VI on UHD in grand fashion. If you count from when the blu-ray/hddvd format war ended, then we’re as far into 4k this year as we were with blu-ray when the 2011 release happened. Even if there’s no unaltered restoration in the works*, I fully expect we’ll hear some official word by the end of the year on when the OT will hit the format.
Lucasfilm doesn’t even have a new Star Wars movie in the pipeline for a 2020 release. That could still change, but Avatar 2 (a Fox release) will almost definitely be hitting theaters in December of 2020. Disney could change things up and put out a new Star Wars movie in November, but it seems likely 2020 will be Lucasfilm’s hiatus year in terms of new theatrical releases and they’ll simply focus on The Mandalorian and this Cassian Andor show, and maybe the saga UHD set could hit later in the year as well. Of course, I could be totally wrong and they’re just waiting until Celebration for the big reveal of a concept teaser for either the Obi-Wan movie or the first part of Rian’s trilogy.
*Like I’ve said before, I really don’t think they’ll bother releasing a UHD that doesn’t at the very least include the unaltered OT.