Changes were made to the films while they were still in theaters.
The versions of the films that people think of as being the original versions are actually edited cuts.
While this is accurate, you are not taking into account the improvement of technology. If (and I will admit it's a big IF), they do release the movies, they would likely utilize seamless branching and multiple audio tracks in order to make this doable. I imagine the release for ANH would look something like this:
Disc One - A New Hope - Special Edition
- Sourced from 2020 Restoration, Dolby Vision
- English Dolby Atmos,English Dolby TrueHD 7.1,French Dolby Digital 5.1,Spanish Dolby Digital 5.1
- 2011 Blu-Ray Cut
- 2004 DVD Cut (with 2004 audio in English Dolby Atmos)
- 1997 Special Edition (with 1997 audio in English Dolby Atmos)
Disc Two - Star Wars
- Sourced from 2020 Restoration, Dolby Vision
- 1977 - 70mm print
- 1977 - 35mm print
- 1981 Re-Release print (with Episode IV - A New Hope added to opening crawl)
- Audio Tracks
- 1977 35mm Dolby Stereo (Remastered)
- 1977 70mm 6-track audio (Remastered)
- 1977 35mm mono track (Remastered)
- 1985 VHS/Laserdisc track (Remastered)
- 1993 The Definitive Collection Laserdisc/1995 THX release track (Remastered)
Discs Three and Four - Bonus Features Galore
Really, lots of possibilities here, but don't need to go into them.
The visual changes between the Special Editions post-1997 are rather minimal. (Yes, it might make more sense to put the 1997 Special Edition on its own disc as there are some significant changes between 1997 and 2004. But the audio changes are minimal at best and even with bigger tracks, they're not going to take up too much space on a 4K disc. As for the potential of doing these different cuts for pre-1997, the changes from the 70mm to 35mm aren't too substantial and the 1981 release simply does the crawl change. Again, the audio tracks wouldn't be too big. Particularly, if they're going to want to keep them as archival editions, they may want to clean up the audio and the video, but if they kept them at a decent stereo, 6-track or mono level, I think that's awesome. No need to go Atmos on these (as nice as that might be).
The point is, this is totally doable. I don't care if they push the Special Editions more and charge me an arm and a leg for these "Archival Editions." I'd pay it to have something like this. But as much as I can dream this up, it doesn't mean its going to happen. And I'm certainly not holding my breath. (My fingers may be crossed though.

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If anyone is interested in an obsessive list of the changes made over the years...
Linky