To get it to run on different platforms and gain new features like super-resolution and so on, yes. Rom files are the preferred form for modifying old games. No one bothers digging up old source code and assets to reconstruct things when they can use an emulator to essentially spit out a derivative binary with new capability. See every re-release of a 16 bit era or earlier game.

Now that I've beat my head against this issue for a while, I think it's best summed up as: weights are a binary artifact, not source of any kind.