Maybe you archive the code on a CD or zip drive in someone's desk.

You delete it from the servers because space I super expensive back then. The nightmarish opening of Silent Hill on PS1 has been recreated in first-person by Zero Trace Operative in this PC fan remake.Zero Trace Operative's YouTube. N64 was a no go except for the biggest most ambitious blockbusters like RE2 and they never would have considered Xbox. Maybe Saturn, but it would have to be early in the life cycle and the game a surefire hit to be worth it. Porting was essentially rewriting in many cases, and in the Playstation 1 era a Japanese company wouldn't have considered there to be any other viable on platform to port to. The game would be tuned to within an inch of its life to run on one specific piece of hardware. It was written bespoke for specific hardware in very low level code.

Back then the game was released and that was it. That may seem silly to us now where games are regularly updated and remastered and ported to new systems, and where consoles are just PCs that use standard high level languages and APIs and even cross platform engines. From what I've heard over the years the idea of retaining source code for released console games was considered a waste of time and space to Japanese companies back in the day.

Silent hill 1 remake