> Clearly if it was able to be leaked it already was being preserved
Preserved by whom? Many leaks are done by old or ex-employees who quietly kept a shall we say 'backup' of their work. More than one 'official' re-release has been rumored to be an embarrassed company quietly filing the serial numbers off a rogue leak because they realized way too late that their archival practices were inadequate.
Anti-emulation Nintendo was caught repacking a pirated ROM.
https://www.eurogamer.net/did-nintendo-download-a-mario-rom-...