Fallout creator Tim Cain says he was "ordered to destroy" his personal archive of the RPG's development: "Individuals and organizations actively work against preservation"
Seems easy enough to preserve old development files long enough to outlast the companies that own the IP. Just gotta not touch them for a decade or two and then "accidentally" find them.
Whoops I zipped them up and put them in a few s3 buckets and kept it on my computer. Oh no, well, you know there's so much that goes in what do you expect.
People wrote in to the Giant Bombcast before to say that they were ordered to destroy code and materials at studios that were going out of business, and they instead hid drives with the files in the drop ceiling on their way out.