From the inability of NASA and the DOD to reverse engineer their own tech from the 60s/70s, to the alleged humor that Blizzard has a bounty for anyone who can provide them with the original WoW code
Media storage is only as good as the hardware and the networks they support, time, corruption, and meat-space disruption will make it inevitable that vast amounts of data will be lost
'Internet never forgets' my ass
Funny you should mention this because something in this vein would be my dream job. Like working in a museum of media as an archiver or curator. And yeah it's very common for companies to just throw away stuff like code once a project is done, only for it to come around and bite them in the ass years later when fans want more of the original.