Or is it? Those games are at most a few megs in size, which means that one can download the library of all SNES games ever made in a few dozen minutes; additionally, emulators are "fairly easy" to implement on new platforms.

This alone guarantees that 30 years from now people are likely to be playing SNES/GBA/NES/etc. games on their hardware of choice. I wouldn't make the same bet about subsequent platforms (like Game Cube, PS2, Xbox, etc.) given a) the bigger size of game files and b) how much harder it is to emulate those platforms.

So those old school games are safe in the distributed hands of the underground emulation community; we don't need publishers here :)